Ive been noticing this recently too also buffering occasionally on random videos from time to time when im having 0 connectivity issues. This isint going to make the average person think firefox is bad but rather that youtube is garbage
I'm one of 5 people who have premium (I use YouTube Music) and they're still slowing down videos for me. Also maybe it's in my head, but I think the Google search has been taking longer too. I've noticed some extra loading time that doesn't show up in Microsoft edge, or if I use duckduckgo/bing from Firefox.
I have had random freezing on the mobile Firefox for months now. I typically search in a private tab with a bunch of trackers disabled. If I do the same search in Chrome, Edge, Samsung Internet (in their incognito tabs) the searches load. This seems like a block on Firefox itself