I run Firefox on Arch Linux on an old Atom-based netbook and on LMDE an old AMD 3200+. Neither have had issues, so it's not the case that Firefox is generically

I run Firefox on Arch Linux on an old Atom-based netbook and on LMDE an old AMD 3200+. Neither have had issues, so it's not the case that Firefox is generically broken on all of Linux.