Just a guess but probably its due to libinput, which is used by default on Wayland. AFAIK it can also be set on X as the default for probably similarly good pen

Just a guess but probably its due to libinput, which is used by default on Wayland. AFAIK it can also be set on X as the default for probably similarly good pen support, but I have never tried - I am more than fine with Wayland.