> It would be a massive undertaking to shift their backlog of videos onto another service, and they'd lose all their existing subscribers and have to build it up elsewhere.

Fortunately that’s not entirely true, IIUC — LBRY and BitChute can automatically mirror their channels. Anecdotal accounts say LBRY pays orders of magnitude more per view IIRC, and doesn’t decrease YouTube growth. minutephysics uses it and still has >5 million subscribers on YT. And failing those, it shouldn’t be too hard to youtube-dl a channel and upload it to a Peertube or GNU mediagoblin (here ’s hoping ytdl starts using git the way its creators intended and moves issue tracking to an antifragile mailing list).