Tl;Dr:
In about:config, I changed these preferences:
- widget.non-native-theme.gtk.scrollbar.round-thumb: false - This makes the scrollbar not have rounded edges
- widget.non-native-theme.gtk.scrollbar.thumb-size: 1 - This makes the scrollbar ‘chonkier’ within the scrollbar region
- widget.non-native-theme.scrollbar.size.override: 20 - This increases the scrollbar region size. Larger number = wider scrollbar
- Make sure widget.gtk.overlay-scrollbars.enabled is set to false - This should have been set to false when you enabled “Always show scrollbars”
On Windows, Firefox follows the system setting (System Settings > Accessibility > Visual Effects > Always show scrollbars).
Not OP but here's one use case. I use FF as a PDF reader, it's faster than Nitro and Adobe opening files and searching within. When I have a 600+ page Admin Guide open scrolling is prohibitive. When I do a text search FF puts location indicators in the scroll bar. A larger scrollbar is better visually and easier to interact with.
Also, what kind of psycho uses a touch screen on a desktop computer?
I use my pc with a “touchscreen” via VNC about 75% of the time.
Tiny scroll bars can suck it.
In that case you set the system to show them bigger, which should affect all apps.
In fact I just tested this, and if I set Windows 11 to "always show scroll bars" (which matches your use case), Firefox immediately goes to full-size scrollbar mode.