If you're on Android, use tubular (https://github.com/polymorphicshade/Tubular). It has no ads, built-in sponsor block and allows you to download videos and play them in the background for music.
If you're on Android TV, use Smart Tube (https://github.com/yuliskov/SmartTube). It basically has the same features as above, but with a TV-friendly UI.
If you're on iOS, consider switching to an OS where a big corp doesn't control what software you can run.