Personally I hate Isekais (most) especially when the protagonist is OP and/or a chick magnet. It’s super annoying as its copy n pasted in so many anime/manga/webtoon/etc.
Theres also when the heroes are fighting someone really strong and they win with the power of friendship or in every battle no one dies or gets gravely injured. They are just fine like nothing happened.
I also hate enemies to allies for like every single enemy. Fairy Tail does this a lot and it’s so repetitive. Like person A just tried to murder you and your friends, is a terrible person in general and all of a sudden you’re cool with each other after one talk about friends!??
Those are just a few I really don’t like. Not saying I hate every single story with these it just depends on execution and originality.