Depends on the game. When the game was made in a way that is easily moddable then installing mods usually just means putting the mod files into some directory. But when a mod is supposed to do something that is not really supported then it has to do even more crazy stuff. And when several mods want to do similar crazy stuff it gets even more complicated.
So it really depends. Though BG3 has mod support built in by now. So everything in there should be easy.
The best thing about it is that they’re not making another BG just because they don’t want to. I think it is safe to say say that they won’t enshitify as long as Swen Vincke is at the helm.
I just don’t get why they didn’t think of quickly porting the Xbox interface over to desktop Windows. Should have been an easy fix to make handheld gaming on Windows more appealing.