Genshin is one of the biggest games using Unity right now, and I doubt Mihoyo would want to take that risk of suddenly having to pay millions of dollars for no reason.
Giving people an exception for using their ad service shows they're happy to apply the rules unequally. I expect a company that is a big litigation risk like mihiyo will be happily exempt from the runtime fee
I install it every 6 months or so to check if android controller support has been added. I expect many other people do the same. It's just a drop in the bucket, but that bucket eventually fills up
Laws and terms are for the poor. I am sure big players like miHoYo, Niantic and Game Freak (Pokemon Go/Scarler/Violet) already have their own agreements and would not be affected by this.