I exclusively use Firefox and I don't have major issues with YouTube. I don't know about the other stuff. However, from what I gather, Google often does A/B tes

I exclusively use Firefox and I don't have major issues with YouTube. I don't know about the other stuff. However, from what I gather, Google often does A/B testing, so different sessions may get served different versions of the same website, and I do see this often. Because of that, sometimes it's hard to pin down where it's breaking. Edit to add: To clarify and be more specific, I watched a live stream on YouTube recently and it seemed to work fine.