In the way Ubuntu is (at least experimentally) supporting a X11 version of fractional scaling while the Wayland option is being fully developed —this X11 version just being a desktop integration of xrandr arcana common between “power users” since some years ago— why no just doing something similar for touchpad equivalent arcana? The additional dependencies are mild:
- libinput-gestures (this is not packaged yet, but seems easy to package, also see below)
The configuration, even if not as powerful nor fancy, could follow the guidelines stated in https://gitlab.gnome.org/GNOME/gnome-shell/issues/516. It could be added as a simple text file in /etc/skel.
This way ubuntu would be (one of?) the only Linux X11 desktop providing touchpad gestures out-of-the-box.
I’m using this since some weeks now and it’s very very effective. Without even thinking about it I’m using it all the time. I have some configuration tips that I can share.
OTOH, I’ve suggested the author of libinput-gestures to package it (and a related GUI independently developed, see https://gitlab.com/cunidev/gestures/issues/17) as a snap or a flatpak. So that could be an alternative, not as convenient as having it builtin but a way to promote snaps (although they still could go the flatpak road instead).