It may also be that Google has just decided that advertisers don't get any ROI on Linux videos. Many GNU/Linux users may be smart enough to use pi-hole or other ad blockers anyway.
@bob what's that? i hear something in the distance? is that... the sound of disenfranchised video creators? are they chanting? what are they chanting? it sounds like peer.... peer what? ah, peertube! it's peertube! the people call for #peertube!