I think it is a combination of these three factors:

So the gap between seasons could be shorter - (work on Season Six has begun I believe.)

Some of Season Five needs to be finished - (I think someone at SDCC said some stuff with the latter half of Season Five needs to be finished so the gap allows them more time to make this season as good as possible)

Movie Production has begun (it's gonna take them a long time to do all that work so perhaps this time is also for that)

that's what I think it might be at least, perhaps someone has a better answer than me.

-2/2-

6.) Make New Friends but Keep Discord: 7/10 - it ranks ahead of the rest because the comedy made me lose my breath several times but I do have some issues. Too many to go into but it was flawed. Still enjoyed it almost as much as any of the top five but there are episodes that I rank lower despite being more quality because I rank keeping quality AND enjoyment equal and this was probably the third most fun to watch.)

7.) Castle Sweet Castle: 8/10 - a nice, relatively calm followup to the premiere -- it shows how much the Mane Six love each other, explores some of the emotions from the Season Four finale that they couldn't dwell on in the premiere and their gifts to Twilight in her home were so wonderful (she has a piece of them in every important room in the castle) . The Golden Oaks Chandelier is possibly one of the sweetest things in the show.

8.) Appleoosa's Most Wanted: 8/10 - I like that the Cutie Mark Crusaders theme this season is learning all aspects of Cutie Marks. It is refreshing that their episodes are exploring the nuance of those marks, it'll make their eventual Cutie Mark episode(s) stronger because it will feel like their grown up enough to deserve them. Imagine without this and Bloom & Gloom them earning their marks, it really would make a difference for the worse because they now can deal with whatever destiny has in store for them. It wasn't strong enough for a 9/10 or a 10/10 but it is solid, entertaining, Troubleshoes is precious and sweet (he and the CMC work well together. ♥) and funny. :)

9.) Tanks for the Memories: 7/10 - 8/10 for Effort - 6/10 for Execution. Heartwarming, interesting concept, It shows Rainbow's loyalty to her loved ones and how far it will go and how Tank has grown to be her best friend. I can't get behind how she got no consequences for destroying a government building and that is a nitpick I guess but if she had gotten proper consequence even with Twilight just saying something like: 'You know you'll have to pay for the damages right?' or 'You know you'll have to tell Cloudsdale what you did and fix the Weather Factory right?" would bump this episode up to a 9/10, easy.

10.) Princess Spike: 6/10 - ...I like aspects of this. (Cadence trusting Spike and counting on him but also recognizing that he might have problems and trying to get him to realize his errors but never disrespecting him or discounting his efforts. It was a nice nod to how he is her hero but also how she is smart enough to recognize that he is still a kid and will fuck up. Spike having genuine intentions for most of the episode, only getting caught up around the end point. Twilight getting some much needed rest.) but it didn't really work as a whole. Mainly because it was Spike's good intentioned efforts that fucked it all up, his greed descent caused none of the problems so the 'Don't Use Your Friends' lesson, while a good one, is wrong because the only good things from that day CAME from him using his friend.

11.) Do Princesses Dream of Magic Sheep?: 7/10 - I still don't know how to feel about this episode which is why it ranks lower despite scoring higher than some. Interesting but flawed. It might fail on it's own OR it might fail because it came after Amending Fences... I still can't tell.

12.) Slice of Life: 10/10 - I just had to count it despite it being a fan episode! What an interesting idea the community had to make their own version of the 100th episode! It was surprisingly subdued and very funny, the fan voices for these characters were great and ... oh this is an actual episode of the show...? The actual 100th episode... of My Little Pony? It wasn't Amending Fences... but this? ... 0/10. (in all seriousness on my first watch I loathed it. On my second watch I approached it as a fan-made episode (it was on YouTube by then which made it easier) and adored it. Actual rank is about a 5/10 with both of that in mind. The intent was truly admirable and I appreciate the comedy and the intent but this was a mess and Amending Fences ruins this episode even more by showing what the 100th SHOULD HAVE BEEN.) ... I consider this a fan-made episode and Amending Fences as the 100th. I'll make up the difference by counting Friendship Games as the Season Five finale.

Overall Score: 93/130 (The Cutie Map being two episodes, it is technically a 17/20) so... this episode passes with about a 70% which is fairly accurate. Good, not perfect and flawed but interesting. If I don't count Slice of Life at all, it's 75% (rounded) if I count it fully: 65% (rounded) (which is barely a passing grade. And exactly why I didn't count it. This half-season is better than the 65% that the 100th would have given it in my eyes. I still had to count it but I was VERY lenient in allowing how I felt about it as a fan episode to count as a half-score. That episode in canon is the worst episode of the series.)

--

Can't wait for the rest of Season Five, with Rarity episodes, possible Coco Pommel, Starlight Glimmer's return and LENA HALL GUEST VOICE/SONG this second half is super promising! ♥ I can't wait for the EQG Movie in September! ♥

So with the first half of Season Five over, I guess I can rank the episodes and give a few thoughts!

Top Five:

1.) Amending Fences: 10/10 - one of the best episodes of the series, great continuity (it really shows how creative this show is that a throwaway scene from the first episode of the show can be developed into such an amazing episode nearly five years later.) Moondancer and Minuette were amazing and Lemon Hearts and Twinkleshine were adorable despite having to be on the backburner. It also subverted my expectations by having her Canterlot be genuine friends to her. It would have been easy to make them social climbing Canterlot ponies who would use Twilight for her princessship or have them uninterested in her friendship OR to have them all resent her (instead of just Moondancer) but they genuinely value her as a pony and they all love her, warts and all. Moondancer's plot was relatable and she got some truly tearjerking scenes. I hope the friendships reformed here will be revisited and that we will see more of this group. This was a lesson Twilight needed to learn and it was done in such an amazing way. How fitting for the 100th episode!

2.) The Lost Treasure of Griffonstone: 9/10 - I enjoyed the humor, the worldbuilding but the star was Gilda, who really is a stronger character than we ever gave her credit for. Going back and watching Griffon the Brush Off with this episode in mind really increases the quality of that one which that fact alone makes this a really incredible episode. I am glad this season resolved Rainbow Dash and Gilda's friendship and made Pinkie Pie and Gilda friends too. I am glad Griffonstone has a nice griffon like her to help restore its glory. (seriously did is make anyone else giggle that she's actually the nicest one in Griffonstone? so cute!)

3.) The Cutie Map: 8.5/10 - the most original premiere we've had and one of the best too. I like the Crystal Empire 2-parter more but this one is a close second (Return of Harmony is a comfortable close third and Princess Twilight Sparkle was technically a three-part finale with Magical Mystery Cure so I count it as such.) I am eager to see Starlight Glimmer return, if it had just been this episode, Starlight would have been the second weakest villain (the first being Sunset Shimmer) but with the news of the finale she has potential to be the second best (behind the Sirens), I also liked the side characters and how important they ended up being and how they saved the day in the end. <3

4.) Bloom & Gloom: 8.5/10 - this was a lesson the CMC (but especially Apple Bloom needed to learn) and I'm glad they did.

5.) Party Pooped: 9/10 - Hilarious and heartwarming, this would make a great episode to watch with Pinkie Pride which really perfectly explore how much she loves her craft and how she isn't just a hyper child, she is a party planner who will do just about anything to help her friends, make ponies smile. It is technically higher ranked than Bloom & Gloom but that one I enjoyed just a bit more (in a different way but still). Still this episode is fantastic!

-1/2-

Applejack is... too good. Most of her episodes can only surround her pride or her family because she's otherwise good. She's exactly where she wants to be in her life, she's the most well adjusted... recent episodes of her have her helping ponies being honest because that is really the only thing that they can do without erasing character development...

... UNLESS they are willing to analyze her behavior-- like how easy it is for her to lie or maybe discuss her parents and show why that family is so important to her. Either that or put her in a situation she isn't prepared for like make her have to focus on business or politics like the comics did... I don't know, I actually agree AJ needs more but I think AJ was developed too much too soon and it causes her to suffer from the writers... I don't know if that makes sense but I'm just trying to think of things.

... I don't know how to respond to this politely so I won't try to. I will say that having 'feminine' aspects doesn't take away from the 'masculine' traits they already have and it actually adds to their characters. If there's nothing wrong with Rainbow/AJ exhibiting manly traits than the reverse should also be true.

In the words of Steven Universe staff member Matt Burnett: 'God forbid a piece of media not include super masculine self-insert super powered hero characters for straight males to identify with.'

I actually do agree with @KShrikePony, mostly from the perspective of: 'why is this a thing I'd see in most bad/one-dimensional fanfiction' -- I believe there is more that could be done. It could have even still been apple-related (in the Nightmare Rarity issues, her dream was related to apples but the Nightmare spirits made her think she couldn't provide food for her family) but just the giant apple? Eh... (although if we had seen the nightmare turn into Fluttershy (her bat-self or her regular self -- either, and some vampire bats, THAT would have been awesome.)

For me, some of the dreams worked and some didn't and that was one that didn't.

I'll admit, coming after Amending Fences this episode suffered, at least for me. It wasn't bad but I found myself missing the stuff Amending Fences brought to the table.

I also found some aspects of this episode a bit lacking-- the dreams were a bit odd, creative in some aspects but a bit annoying in others. I think if the dreams were more similar to scenarios like in the Nightmare Rarity comic, than I would have enjoyed them more. I liked Pinkie and Rainbow's dreams but the absurdity made it work, especially Rainbow's, and the other four felt way too much like fanfiction... I get why this was done but I would have liked to see a bit of character analysis in the dreams. Ponyville's dream was much the same absurd that PP/RD's were (but better because the lack of a scenario/character specific features works because it is a very stretched shared dream) I found it so ridiculous it made me laugh and therefore I enjoyed it.

The strength here was Luna, I really felt for her and her guilt. The conflict she has is strong... though perhaps it should have come earlier. I think this episode might have been better toward Season 3 or early Season 4. By now, it perhaps feels like she should have had someone sit her down and tell her how valuable and good she is now. With how guilty she is the Tantabus only escaping now feels ridiculous. Still it was really emotional and good and the end was heartwarming as she finally grew beyond her guilt.

I feel like I'm being too critical because if it hadn't been after one of my favorite episodes of the series it probably would have been better to me but it did so there's a lot more things I'm seeing that bug me. I give it a 7/10. (most of it did work but a few things really didn't and if I didn't think I was being unfair I probably would have given it a 6/10)

Or the storytelling of this series is non-linear and therefore this could very well be BEFORE Tank went into hibernation? Who knows.

If the continuity is broken and no hibernation (which we really cannot claim because Pony has no set timeline) then... wouldn't be the first time, it sucks but this lapse doesn't ruin anything (at least for me) and if it isn't and this is after, then... what's the problem? I don't know how you can claim they haven't grown even in the fairly short time between Tanks for the Memories and this episode, it isn't a LOT sure, because this season is only now halfway over and one was wasted on the 'Pandas and Shark Jumping: Totally a Fan-Animation Accidentally Aired' episode but still they have progressed and really, they have been growing so much that it's become hard to notice. Besides, this isn't a character focused episode (well, it is for Luna but... not for them) so it's not a crime to not overtly show their virtues because the focus should have been and was on Luna.

I thought that this would have made a much better episode 100 and I think I'm honestly going to edit that poor fanservice dreck in my mind as a fan made episode, make Amending Fences the 100th and make up for the missing episode by counting Rainbow Rocks as the true first episode of Season Five. This one was heartwarming, full of growth for Twilight, the character that the show grew with and a testament to friendship. Plus it has parallels to the pilot. My only complaint was that Sunset didn't cameo in the flashback as a teaching aid (which would have been neat and also connecting her to the actual universe of the show) and that Lyra, probably due to her being in that totally-an-accidentally-aired-fan-made-episode, didn't show up. But this honestly for me, was the best episode of Season Five so far and it so greatly captures what I think the 100th episode tried and failed to.

Now here's hoping Octavia and Bubbly Muffins show up in other episodes of Season Five that I can actually count as true appearances.

I really <3 #3, I think she's probably my favorite, simple yet so cute, has a charming appeal and FRECKLES!