I was going to make some smart ass comment about browser version numbers being ridiculous anymore (after Firefox 3.6 I stopped keeping track), but then I saw it

touchpad & touchscreen gestures, swipe-to-nav

Hot diggity damn. This might make me less likely to revert to Chromium every new install, if Firefox works well with touchscreen at last. I'll have to check this out on my Pi 5 on Ubuntu.