

Some distros are more fragile than others. Stuff like not having the Nvidia drivers installed by default (I’m assuming for the llvmpipe issue) are sometimes discussed in installation guides. IDK if Ubuntu has one since I don’t use it.
Blink-based browsers (like Vivaldi, Chromium, etc.) IMO kind of suck on Linux (or at least Wayland). It’s probably worse with Nvidia cards since Nvidia is still sometimes flaky on Wayland.
The LibreWolf issue is maybe not an issue at all. I’m assuming you mean RAM, and if so, browsers just like to eat as much memory as they’re allowed to eat. If you open up something else and it needs the memory, LibreWolf will likely let go of some of it. There are probably some knobs you can dial in LibreWolf (or Linux kernel settings) if it’s really an issue for some reason.
I only really have issues when I’m trying to set something up that’s not already configured by the distro (or if I’m doing something particularly weird).
I feel attacked.