[pwinnski]

It's easy on the creators primarily, they get to skip a lot of steps and don't have to explain away things like cell phones.

For consumers, they get quantity.

Although it shouldn't be impossible, it seems really hard to get any kind of real quality out of isekai stories. Usually the stakes are low and the setting is surprisingly similar (even though having a different setting is ostensibly the entire reason for the genre). All you end up with is variety in characters, and even then there are common tropes.

[dageshi]

As you said, the readers get quantity and honestly above all else that's what they want.

They already enjoy the stories enough to buy them or support patreons for them, I don't think trying to up the quality would be wise for the authors assuming it slowed down how quickly they wrote.