NewPipe [1] and its derivatives like Tubular that include SponsorBlock (and dislikes, but I don't use this feature) are also great.

They let you follow channels and build playlists without a Google account and play stuff in background.

You can find those apps on F-Droid by adding the relevant repositories.

[1] https://newpipe.net/

[2] https://github.com/polymorphicshade/Tubular