It's mostly libinput. Why the hell can't I easily change scroll speed on Gnome and not on KDE? Why does gnome have a simple tool (gnome tweaks) to change the trackpad cooldown to change the time trackpad doesn't work as a substitute for good palm rejection and KDE doesn't? Why is it a bit of a pain in both to change trackpad gestures? Why am I hearing again about God damn redesigning the settings placement on most desktop environments.

Edit: I love both KDE and Gnome, and I think that they're great. But it kinda hurts to see them fail on what seem like relatively simple things