What are you talking about? Firefox hasn't been single process since more than 10 years ago. At most, it uses 7% for the main process and I have thousands of tabs open. I can't talk about the other two, but I've had processes use 60% of the system memory without problem (everything else is slow due swapping, but that's expected).
They were talking about instability. I had an old Radeon workstation card in my desktop at home for at least a decade, but with the most recent AMD drivers, Firefox (with hardware acceleration turned on) would crash Gnome and the system when watching videos on YouTube. So I wasted money on one of those new Intel graphics cards to get the stability back (in addition to the time wasted diagnosing the problem).
That seems more of a gnome issue than otherwise. Right now my firefox process is clocking +8h of cpu time, I have 3 youtube videos on pause. My last crash was 2025-07-31, so yeah, I would ask you all what kind of system are you rocking instead.
