Looking at them for what they are meant to be, there are only a few things I'm truly disappointed about in these games. One of those is the size scaling during battles and in pokemon camp. It's just so off to see so many pokemon looking either far larger or far smaller than they are meant to be, and it's especially jarring since in the overworld and in cutscenes they are at least close to the right size (i.e. your starter seems to increase like a quarter in size between you choosing it in the cutscene and the battle with Hop). And of course, the more extreme the sizes, the more you notice (i.e. how infamously small Wailord and Eternatus look).
It's easy to see this is due to some kind of limitation in the battle arena graphics system (or whatever might be the proper term for it), that the pokemon has to fit within a certain space between the trainer and the opponent on the screen. One also has to consider that they want both pokemon to be readily visible to the player, even if one is a foot long and the other is thirty feet long, but I think routinely zooming in on the small pokemon could make that work.
On the other hand, there are also cases where the pokemon looks smaller despite there seemingly being plenty of room to make it look larger (i.e. Tyranitar). It also doesn't explain why the sizes are off in Pokemon Camp, which one would think can work the same way as the overworld pokemon. That they did bother to make the scaling better in the overworld makes me really curious how much harder it is to apply it elsewhere.
The fact that I am ignorant of how difficult it would be to implement means I want to give Gamefreak the benefit of the doubt. At the same time, since they are basically halfway there already in having the pokemon be the right size (i.e. doing it for overworld and cutscenes already), I am hoping that next gen they can go all the way. We know proper scaling can be done, it was done for the Battle Revolution game, and perhaps whatever programming was used there could be copied or somehow applied to the system used in the mainline games. Heck, I'd even settle for larger pokemon just being positioned the way Dynamax pokemon are behind the player instead of in front, if this makes the programming easier.
This criticism comes from a place of love, as I love seeing the pokemon at their proper sizes in the overworld and would like to see it applied to the rest of the game. It makes everything feel more real and diverse, with the creatures that tower over you and the ones that run between your feet.
Likewise, them having and using walking and running animations for all the pokemon, and having smaller dexes to decrease the workload, makes me hopeful that following pokemon could come back as a mainstay feature. At first I thought this was unrealistic, that it'd be something reserved for the Let's Go games, but since now its looking like Gamefreak have no plans to continue those games (they sold well but it seems lacked the staying power they wanted), perhaps there is a chance to see it return.
This has been my positively hopeful monologue for the day.