What's the worst new feature you could see them adding next gen?

I made this a few days ago but it got taken down after an hour and I was told to repost it Thursday

So we've all had heated discussions about the value of Tera and Dynamax and whatnot, but what fresh addition for gen 10 would make you jump ship? It can be a big generation-defining change like a new Type or gimmick, or a small change like Stat buffs and nerfs. Just try to make it something that you could within reason see Gamefreak doing rather than "every move now has 200 BP"

Here's my example: You've heard of Critical Hits, now get ready for Critical Fumbles. Instead of dealing extra damage, the Mon screws up and only does half. On top of making your team feel more relatable since everybody makes mistakes, this will better emphasis the chaotic and unpredictable nature of Pokemon battles that helps makes them so fun!