There are apps like NewPipe that pretend to be a regular browser but show the user an optimized video interface. And no ads of course.
They’re in a constant arms race with YouTube to figure out where the actual video and the other stuff (comments, video info, related videos etc.) are on the page, and YouTube keeps moving them around on purpose too.
Depends how far they’re going to take it. If they’ll focus on people with a YouTube account and threaten to block their YouTube/Google account, it’s one thing. You’ll be able to work around it by using incognito mode (assuming you trust they don’t spy on you in incognito mode…) or a browser where you’re not logged in, or NewPipe etc.
If they threaten to block people who aren’t logged in (by IP and by the fact they already spy on your phone and know your Google account) then it’s another thing and nothing will be able to bypass it. They would burn a lot of bridges by doing that and expose themselves to some huge fallout and scrutiny about privacy, but you’d have no choice but to watch ads or not use YouTube.
But this is such a shitty, hostile way to do it. And if you give in and say yes to ads they’ve already shown where that’s going to go, with 10 unskippable ads in a row and 30 second ads.
They could make subscriptions mandatory if they really believe they have a good product, and pass a fat portion of that money to the creators instead.
…except this isn’t about the creators, or the users, or the advertisers, it’s about Google making more money at the expense of every single other party involved in the platform, and the platform be damned. Textbook late stage enshittification.
They’re more like PO boxes in this case.