I'm not into watching gaming at all (I'd rather play), but this is really just another twist on 'Reality TV', and one with less dysfunction IMHO.
It's too easy to turn off my brain and be 'entertained' for hours. I've recently forced myself back to watching films/TV instead. The difference in creative stimulation is like night & day.
Never say never. I am sure there are people who do, probably not with much success.
Its this play by proxy I now think is one of the main draws.
I have been encouraged to stream by others myself, and do every once in a while on hitbox. Maybe I should give it a real try.