That implies that it already existed in X11 environments?
Not necessarily. Especially in the gestures department, those tend to be Wayland exclusive and is probably why you need to press Alt on X11. I think applications pretty much only get scroll wheel events on X11, while on Wayland they get proper touch events so it's possible to also implement pinch to zoom and the other usual ones.
Both Gnome and KDE only support 3-4 finger gestures on Wayland as well, like 3 fingers up for overview in Gnome just like macOS.
I would expect Wayland to work great on a Chromebook, I'd recommend giving it a try.