Unless you're a VERY large and successful YT channel, you aren't making bank on YT itself, it's merch and sponsorships, Patreon and so on that make the money. Monetized Twitch-like feeds are another winner, and again not dependent on YT monetization.
That does not answer the question. There is floatplane and Nebula, but beyond those where will be the content be hosted and will those revenue stream actually cover those hosting/development costs and running the site?
And on other hand if users are paying you something, would they not expect not to have to watch through mediocre sponsorships?
The point is that many successful YouTubers wouldn't be broke if they stopped making ad revenue from YouTube, because they make most of their money elsewhere anyways.
How will your content get served? If you say you'll just pay to serve it, I think that's a fine answer.