For those wanting to build a Wayland-only Linux desktop experience without carrying any aging X11 baggage, GNOME 47 will be able to optionally offer Wayland-only support without carrying X11/X.Org support. This Mutter merge request landed today that allows compiling Mutter with X11 support disabled. That landed today along with this GNOME Shell merge request for being able to disable X11 support too.
The article you posted is outdated. The last change was in 2022 and most sections are even older. Plasma 6 has full Wayland support.