I'll pitch in that since youtube was bought by Google it's become pretty anticompetitive too. They've absolutely been caught degrading their product on all browsers except chrome. I've witnessed this numerous times on Firefox on my android. Videos refusing to play, subtitles appearing off the screen, refusing to fullscreen, and at least 3 more annoying things i can't remember anymore.
I'll pitch in that since youtube was bought by Google it's become pretty anticompetitive too. They've absolutely been caught degrading their product on all browsers except chrome. I've witnessed this numerous times on Firefox on my android. Videos refusing to play, subtitles appearing off the screen, refusing to fullscreen, and at least 3 more annoying things i can't remember anymore.
This is incompetence, not malice. YT devs would skip testing on Chrome if they could get away with it, but are forced to.
On numerous occasions, I had issues with YouTube and Firefox that were fixed by changing the user agent to make it look like chrome.
I stopped using YouTube 10+ years ago, so no clue if it still the case.