Isekai was a thing before the word was popularized and normalized in the west to describe the subgenre of fantasy. I'd argue The Neverending Story is clearly an isekai, for example. And there's been great conventional anime isekais in the past, such as Vision of Escaflowne.
What I'm sick of is the "oh this is like a video game and the NPCs can be manipulated because they're just programs susceptible to cheat codes" gimmick. It's gross and I find it intolerable to follow any "hero" that dehumanizes other characters under any excuse to build a virtual capitalist empire with an infinite harem. It's :epstein: tier :brainworms: to me.
I don't want to automatically reject something I hear about because I hear it's an "isekai" but all too often it means "another video game world with NPCs to exploit!" :capitalist-laugh:
What an empty sort of metagamey victory to fantasize about. How alienating and sad for such "heroes," even if they still deserve :gulag: in general.
Sorry was at work earlier so I couldn't give a longer reply, and I kinda want to address this cos I think it does raise an interesting comparison:
OPM kinda does that, in a postmodern ironic sense, but it hyper-fixates on the alienation of labour (why Mumen Rider is sorta a foil character to Saitama, in that he's the true proletarian hero who is not alienated from his labour but is completely disempowered and he just like me frfr), and imo one of OPM's big failings is that it gets lost in the sauce and doesn't posit a way out of that alienation, to the best of my knowledge. (I haven't followed OPM in a while, although I read the manga a bit further on from where S1 of the anime adapted.) Funnily enough, it's like criticism of Mark Fisher's work on Capitalist Realism we've seen sometimes, in that it's not enough to point out that we're stuck in capitalist realism but we also need a way out. Not that I think it was on Fisher to supply that answer.
CSM is kinda cuts out the irony in favour of this over the top absurdity (in the Camus sense) that's part of the point, that "life under capitalism is just a bullshit sandwich so why not have a cherry on top" kinda thing, coupled with a deep, deep, searing sincerity. It's post-postmodern, and it cuts to the quick in wasting no time in pointing out what is wrong with the world from literally the first chapter (spoilers: that the powerful want more power and will step on everyone else to get it) AND it posits a solution to that problem, even if it is a classic: Eat the Rich.