I don’t experience any lockup’s. I switched to Firefox as my main browser on Linux and macOS over a year ago full time. Google Meet finally works properly with it, so I don’t even have to use chrome for that last thing.

I don’t know what you’re doing, but I’ve never had a lockup in that entire time (and I run Beta), as far as I can tell, it is the fastest of all my options.

The very last thing that I notice any difference on is energy usage, for which Safari is still king. I don’t use Firefox on my iPhone, as there’s not much point (I wish Apple would change their restriction here).