Wayland. It comes up a lot: “Bug X fixed in the Plasma Wayland session.” “The Plasma Wayland session has now gained support for feature Y.” And it’s in the news quite …
I switched my laptop to Wayland ages ago. One screen, not used for anything complicated. KDE Wayland had everything it needed years ago.
My desktop PC is used for gaming. XWayland Freesync, multiple screens at different refresh rates and DPIs and so on. Wayland was missing support for things it needed until fairly recently, but even it got switched over last year.
Wayland is pretty mature now, and devs are chasing down the last edge cases.