Comment 3 for bug 1762551

I have to disagree a bit about the the duplicates here. This very old bug was when Firefox was using GTK2, and back then the scroll bars in Firefox were GTK2-standard and didn't use the overlay scrollbars (up and down buttons).

All the newer bugs have GTK3 Firefox, and that the scroll bar in Firefox is thin and does not expand, or is not thick by default as in Adwaita. In Adwaita, the scroll bar is already thick and easily handled.