Meanwhile I feel like on my Linux laptop Firefox has only been getting slower and slower every year. Perhaps the fact that I'm using a GeForce as my primary GPU can have something to do with it? I read it causes some problems with WebRender. Anyway it's sad to see Chromium being way snappier on my machine, I have to use it for meetings because just after a couple minutes audio in FF starts to stutter intolerably.
Some time ago I removed a whole bunch of packages from my system I hadn't used in a long while, and turned out I also accidentally removed the "pciutils" package which turns out to be a runtime dependency for Firefox's hardware support.
Without it, regular things were significantly slower, especially if images were involved, even on simpler sites. Just installing pciutils again instantly made a huge difference.
