Gnome has built in gestures for the 4-finger swipe, but they can also be extended to more 3/4-finger gestures by e.g. https://github.com/mpiannucci/gnome-shell-extended-gestures. But they only work on Wayland but not XOrg. On the other hands, a 2-finger scroll works no matter which display server protocol is used.
I was wondering about why this is the case. Why does this depend on the display server protocol? What are the technical insights behind this?