I thought it would be great to spread awareness about this issue, hence I'm sharing it with you here.
In X11 there is a nice feature called "Turn off touchpad while mouse is plugged in" - it's a lifesaver when you have a laptop with big touchpad; me and lots of people with this issue accidentally hit it all the time while typing.
However in Wayland this setting is missing. After some digging people found out that this is not an issue with the libinput driver itself (used for touchpads on Wayland), as it is supporting this feature for a while now; rather it's an issue with the settings app itself, simply not implementing this feature while using Wayland.
Hope this will get attention from the community, as the recognition from the dev's side is minimal.
@JokaJukka Have you tried switching to X11, enabling the setting, then switching back to Wayland? Does that do anything?
Unfortunately this simple trick does not work. It seems to be a backend issue too (not just missing button).