TLDR: NewPipe 0.27.6 fixes the YouTube issues by performing the integrity checks now required by Google; NewPipe is being refactored heavily on the refactor branch and you can help and provide feedback on a nightly version; NewPipe will soon have a new completely rewritten player; the NewPipe team is struggling to keep up with the project’s demands due to dwindling free time of its members.
I haven’t been able to get ReVanced working for a while. This is a standalone app that let’s you watch YouTube without ads and plays while the phone is locked?
Greyjay?
Not open source but source-available and trying to push alternate platforms.
Yes, that is correct. It also has support for peertube, SoundCloud, media.ccc.de, and bandcamp.