>>41479027Gamefreak are very good at designing characters, both Pokémon and humans. But they're absolutely terrible at rendering them in 3D. They can't animate properly, they can't even optimize storage and usage of models and pull dumb shit like storing a model for Lillie in every single area of the game.
What I think the problem is, is that they spent and still spend WAY too much time on the character models in 3D - the HUMAN characters, not the Pokémon - for some inane reason. Even XY with its low poly style looked GREAT most of the time; it was the cringey battle and cutscene models that not only ruined it but also couldn't even render multiple at the same time (go look it up, the models of your friends in the ending are 2D!)
Back to the point at hand, 2D sprites allow them to condense the admittedly very good character designs into a representation. By comparison, the Pokémon designs get a much better representation in the form of 2D battle sprites, and in the case of gen 5 they were all done EXTREMELY well. Not just moving in a way that portrays their character, but also having them be just dynamic enough and also just representative enough that not every single one has to be totally unique to get the point across.
In theory, 3D modelling should have future-proofed this, but firstly they modeled every single Pokémon in the absolute most BORING manner possible, and secondly they seem to have decided they don't actually want to use them anyway.