Last time I used it I had a lot of videos that didn't play and would frequently have to use the browser or YouTube app to watch them. Maybe +50%
Discussion
YouTube sometimes changes the way their backend works, and their is a lag for them to update pipepipe to work around it. I use it daily and haven't had issues in months FWIW.
I just tried out grayjay for the first time and it's working great
Grayjay is good too. It's nice that it has multiple video plugins.
If you need to download vids check out
https://github.com/deniscerri/ytdlnis
It can dl from YouTube and hundreds of other web sites.
I use NewPipe, more stable than PipePipe, but w/o the SponsorBlock