Most of Nintendo's high-end franchises have been able to "evolve" except for Pokemon. Even the proven -to-always-work ones have taken great steps forward. For a franchise based on an RPG that honestly has plenty to pull from it's resistant to make itself better. The progression of a pokemon game becomes to expected and bland and to some extent it stops making sense in its own world. People have been making suggestions for years now and it's pathetic they refuse to listen to it's base. Scarlett and Violet should have been it's death but people still bought into it so again, it works for sales so why would they need to add in extra resources? Once I picked up on the gimmicks (z-power and gigantamax) I knew it was getting ridiculous. The game just straight up relies on predictable concepts of grinding and higher levels encounters through progression yet it tries to pass itself off as openworld and non linear when you have orher games who clearly do it better. If a pokemon game held it's same concepts and was called somethings else like Master Catcher or Battle Critters it wouldn't even be considered as "great" as it is. You can't say the same for the other franchises.
It's why all the side games made by other groups are often so much better than the mainline games, despite having a far smaller budget to work with. Because they actually try to do new and innovating things with the franchise.
God mega evolutions we're such a great addition in X/Y. Z moves were lame and I haven't played a new Pokemon game since alpha Sapphire. Like yeah it's Pokemon but it just feels like a product at this point. I know the point is to make money but maybe they should take a break. Pokemon games almost died in black and white because they haven't changed.
You're right that mega evolutions were great in that it gave certain Pokemon a second chance to be useful however even that took a wrong turn when they mainly focused all mega evolutions to to all the popular Pokemon who were already great to begin with. On top of that, it did continue forward which I feel would have been another opportunity to give those not-so-great pokemon that chance.
In a vacuum Megas were fun, but I think they were a net negative to the games as a whole.
In the single-player game, it's basically an instant-win button. I don't think pokemon needs to be difficult- I find most rom hacks and nuzlocke runs tedious and annoying. But having one button that just wins felt bad. The whole concept of temporary transformation felt like something that didn't belong in pokemon, probably because its absence was something that separated Pokemon from competitors like Digimon and Yu-Gi-Oh.
Before Megas, new mechanics were usually things that made sense. Things that fit neatly into the world, may have been in the anime early, and were pretty logical conclusions that were only not in earlier games due to technical limitations. Splitting Special into SpAtk and SpDef, splitting moves within types by Phys/Spec, adding Steel type, Held Items, abilities, double and triple battles, breeding. To me, Megas felt drastically different, as do Z moves, Dynamaxing, and Terastillizing.
yeah i have enjoyed the new games but none of them have really been able to capture the magic of the old ones. dexit also didnt help.
somehow collecting all the pokemon felt more fun in the old games? i mean it was always a chore to do, but i remember being much more excited finding a rare pokemon in the older games than the new ones haha
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.