Well, about that...
Gen 5 was considered a LAUNCH title for the 3DS (in North America at least), despite being designed with the DS in mind. And it was coming after Gen 4 which had it's entire lifetime on the DS hardware, so this not the FE-Awakening scenario where a title is adjusting to the new hardware but a final hurrah on a system's twilight years. This is supposed to be a culmination after years of polish, not a first try in the new sandbox.
And let's talk about Gen 4 because Platinum and especially HG/SS are a lot more "crisp" in comparison to Gen 5. Sure that's because the sprites mostly stay still (beyond their opening pose), but they just look a lot cleaner and solid in comparison to Gen 5. And I'm not just talking about the battle models. Replay Gen 5 and go to either Castelia City, Village Bridge, or White Forest/Black City, anytime the zoom on your character changes and watch how... glitchy... the characters get as the focus zooms in and out. Compare this to Goldenrod City, smaller in scope that's for sure, I won't deny that. But it just looks a lot more sharp.
I'll skip how Gen 5 looks a little worse on the 3DS XL because that would indeed be unfair.
And why's it unfair to call out something you don't agree with? Even if it has it's reasons, ugly is still ugly. it's not really "ugly" but I'm using stronger words to emphasize my argument
Now, I'm not saying that Gen 5's art direction with the moving sprites or world design was a bad idea. They were trying to do something, and I support trying something new yet making a few mistakes. I think it's more like your awkward teen years, necessary to grow into the adult you are but not without acne (or in this case pixelation).
In fact, one thing I really liked was that in B2W2 they gave all the trainers their own battle opening poses which was really cool and I was sad they took that away for Gen 6 but I'm really glad it's back for Gen 7. I also really liked Unova's increased "urban fantasy Earthbound" feel in town and route design.