mtp has nothing to do with the display server. X11 has no mtp function either. its completely independent from that.
and i can only talk about KDE, but it has a own solution integrated which then mounts android folder in its file explorer (dolphin) while unfortunately blocking mtp over CLI at the same time. you get an “likely in use by GVFS or KDE MTP device handling already” error then.
It is possible of course that this is a thing that happens only under KDE wayland, but not because it is wayland itself but because the wayland version of KDE is maybe newer or was configured differntly by the devs.
that said, if it does not work as expected, report it as bug. usually things are fixed very quickly.
I don’t see how this is a Wayland problem. X11 has no desktop automation integrated either. You had to use third party tools for that like Autokey. And admittedly, there is still no comparable replacement for Wayland as far i know (maybe KDE scripts? https://develop.kde.org/docs/plasma/kwin/api/ or https://github.com/ReimuNotMoe/ydotool?). But that is because nobody has fully build one yet, not because some inherent absence of necessary wayland functions.