They stay unprofitable forever individually but they stay on YouTube instead of making another video site popular, which on the whole is better for YouTube.
But that isn't an as big deal as it sounds. Many use TikTok for example, but TikTok barely pays anything to creators so anyone who gets big on TikTok moves to YouTube to make money. As long as you make the most money at YouTube that will keep happening, and all those ads is why people make so much money making videos on YouTube.
This leads to an Apple situation where Apple doesn't have the most users but most of the money goes to them since they can extract much more money per user. It isn't a bad situation to be in.
I would agree with that if most of the costs of YouTube were paying the creators, but my guess is they're not. If YouTube gives, for example, Vimeo the chance to become big enough and they just happen to be more efficient than YouTube and also decide to pay the creators just a little bit more than YouTube, isn't it even a tiny bit reasonable that maybe Vimeo could gradually replace YouTube in the future?
Of course Vimeo would have to fight off adblockers too to compete in money extraction with YouTube but that's not my point, my point is that YouTube now has a monopoly and any actions that threaten that, such as strongarming people into watching 3 preroll unskippable ads, are in my opinion silly and self-defeating.
They're just too greedy. If they made the price of YouTube Premium something reasonable ($1 or $2 a month instead of $14 or whatever it is) they would get a lot more subscribers and probably even get more revenue. $1 or $2 is not worth spending even 10 minutes digging in obfuscated JavaScript to fix an adblocker, so this whole thing would go a lot smoother for them if they charged that. Even if $14 is not a lot people just don't want to pay that much.
This leads to an Apple situation where Apple doesn't have the most users but most of the money goes to them since they can extract much more money per user. It isn't a bad situation to be in.