I would argue Pokemon has "evolved" too much, to the point where the game is bloated with way too many mechanics and is trying to be too many things.

You mentioned Z-mkves and Gigantamax. I would add in Mega Evolution, the Fairy type, Dynamax, Raid Battles, open areas. There's a ridiculous amount of unique and dumb evolutions. There's about 3x as many items as there should be. They keep on writing epic "kid saves the world" stories instead of "kid pushes back against the inconveniences imposed by small-time criminal" stories.

A lot of Nintendo's franchises have had BOTH transformative new games AND new games in the older styles. Mario has consistently had both 3D and 2D releases, on top of all of the sports games and other spin-offs. Metroid had the Prime series and then Dread. Donkey Kong had 64 and then went back to 2D. Zelda has had 3D games for sure, but they have also had 2D games like Link's Awakening on the Switch and previous handheld games.

I think GameFreak needs to grow and split into 2 teams: one to focus on 3D open-world Pokemon (like the Legends series) and one to focus on more traditional, 2.5D. Each team could take 2 years/game and they alternate releases. The 2D studio could add in re-makes as well: I am hopeful we get a Gen 5 re-make soon, but we are also getting to the point whete slme of the first re-makes are starting to need re-makes, like FRLG and HGSS.