I feel like they run it poorly. I would never condone myself to live like a caveman, especially if I could solve it. Who would want to wipe their butt with leaves, and use a dog turd as a lozenge. We romanticize fantasy worlds and ignore all the other issues that come with them. I feel like games almost make this tunnel vision effect worse.
I try to cover a lot of different things when I write isekai, I feel like games have a harder time with this because of player choice. There are lots of awesome ways it could be done for games. If they made a red dead style shooter in a fantasy where you were an outlaw making your own firearms and gunpowder to rob fantasy buildings would be awesome. You could even make it a bit like payday, only fighting orcs, elves, beastmen.
I literally just came up with this off the top of my head as I was writing this post, but I mean it can be done. I feel like the game companies are to worried about telling the story of the world, and that kills the isekai experience.