Completely off topic at this point but I’m curious what video card you have and if you’re on X or Wayland.
My Linux box at work is an HP laptop from several years ago with a pretty basic business class AMD graphics card in it, I did have to install AMD’s binary drivers on this machine.
And, using Slackware, it’s X. Not sure if Wayland is easily installable or not on Slack but it’s certainly not part of the base install or supported by Patrick.
Firefox is the only piece of my install that isn’t part of official Slackware-CURRENT.
Other than running it in Windows all of my other computers that use Firefox are running stock, no fancy desktop versions of Slack or OpenBSD. I use calm window manager on both. (Sorry, this contradicts an earlier statement, I also had to compile and install Calm on Slackware from source, everything else is just part of the supported packages for CURRENT)
Maybe my low resource OS’s help?