if you are on android can probably download and side load the apk for a while? iPhone would be harder. There are alternatives like newpipe, and I imagine eventually someone else will create a new fork/project. there is lots of discussion on the reddit thread about what to do now https://www.reddit.com/r/Vanced/comments/tdazfr/discontinuat...

personally I just only watch YouTube on my laptop with blockers that remove all ads and using emby on mobile/tv. I never was willing to put my google creds into a non google app.

I use just plain Firefox with uBlock Origin and tend to stay away from content with sponsor spots. Personally I haven't seen a YouTube ad in years.

If it was only about the ads then I might consider it but I want OLED black and SponsorBlock too

EDIT: Also automatic different quality on mobile/wifi (dunno if original app has that)