Ruin Pokemon with a Single Change

[Hermione Granger]

- Gym Leaders Pokemon is always 15 levels above yours with perfect stats and moves.
- Your Pokemon always disobeys your commands regardless of how many badges you have
- You can't save your game until you beat the elite four and champion
- You have to buy your Pokemon team members with a maximum party of three team members while rival trainers being allowed a full team of six Pokemon.

There I ruined Pokemon for you.

 

[Gardevoir1]

Enemies get twice as many turns as you and they always go first

 

[Corveone]

Make it more like the Anime (add characters from the anime, give all Pokémon their anime cries, let the power of friendship even bypass type match-ups, etc.)

And

Make it open world.

I second this. I mean, I'm fine with pseudo open world as in Legends Arceus, but I don't think a true open world structure would work in these games.

 

[Megan]

I was so tempted to say "bring back HMs" but people have already said that a couple times.

So, here's another one: remove the EXP-Share.
I'm not saying that you can turn it off and I'm also not saying that it becomes a held item: no, just remove the entire thing and bring back the grind. Gotta teach people these days to appreciate hard work. :3

You can even combine that with level requirements. "Your entire team needs to be at least level x in order to proceed"