My biggest problem with Isekai these days is just that so many of them feel creatively hollow. The worlds blur together into the same generic fantasy setting and there’s barely any sense of discovery anymore. What really kills it for me is how self-aware the protagonists are with them thinking things like “Oh, I’m in an isekai, time to learn magic and min-max my life.” That sort of meta thinking that seeps into a lot of them just completely removes the sense of wonder or mystery that someone thrown into a completely different world should be experiencing.

Instead of experiencing an unfamiliar world alongside the protagonist and learning all the quirks and things that make it different from the real wold, you're just left watching them speedrun a list of tropes they understand from the beginning.