Youtubers generally make more from sponsorships than adsense, at least from what I've gathered. The reason to still run adsense even though it might annoy your audience is that if you don't you get penalised by the algorithm.

Where I could easily see peertube taking off is with public broadcasters and generally media companies doing video that's free to view, as far as youtubers is concerned I wouldn't be surprised if e.g. nebula started to federate... they can still have a "paying customer vs. free content" type of separation while probably saving on bandwidth costs.

A big thing would be the likes of vimeo seeing this as an opportunity. Unless you're already running such a platform you probably don't want to get into the business of contentid and copyright strikes and would restrict your platform to well-known and/or paying actors, or, well, yourself.