>>112783246I can't really see it happening in the West. It happened in Japan because pretty much every anime is an adaption of some book or mobile game made a year or two into its run to point where it's basically an obligatory tie-in: if your LN is even moderately successful, it gets an anime. And those mediums have follow-the-leader stuff be super prevalent thanks to how relatively quickly it is to pump out a knock-off of the new popular thing. Hence all the isekai shit that has plagued every anime season for the past decade.
The Western market isn't structured in the same way, so even if we do end up with a bunch of isekai shows at the same time, such a trend wouldn't last as long (look at last decade's "teenagers in death games" craze in film) and still only consist of a fraction of our cartoon output. The current situation of Infinity Train, Owl House, and Amphibia doesn't even feel comparable, because while they're all "MC whisked away to a new world" shows, all the worlds are actually different (sci-fi, medieval fantasy, agricultural) rather than sll of them being some medieval fantasy world (with RPG mechanics!) like every work in OP's image.
