I don’t know the current state of things, it’s probably more than 10 years since I’ve bothered with rooting and custom rooms and such.

But back then I remember my phone company tried to make me pay extra for tethering and there were a few tricks using root to get around it. I think there were a few apps out there that would work on the stock room that needed root, and I think it just worked out of the box with a custom ROM.

IIRC, at that time, my carrier had disabled the tethering options in the phone settings, and to tether you had to use their pre-installed app. My memory may be fuzzy on that though.