My games, which are not using any special Chrome features, work horribly on Firefox and not at all on Safari. Until that is fixed no amount of bullying will make me switch. Not that it's a successful tactic to begin with.
Did you try to fill bugs in Firefox's bug tracker?
I have and actually gotten a couple of them fixed in a timely manner. One was even marked with highest severity so it's not like I'm hallucinating this or doing something wrong. The team clearly cares about fixing performance issues. With that said, it's not always easy to create a minimum working example reproducing some things (general low fps, stuttering, unstable rendering, sudden black screens, strange audio artifacts).
Thank you for supporting Firefox then.
Do they work in Brave? Still Blink, but removes Google's direct control of your browser and many of its misfeatures/malware.