Soon ... don't believe it. Wayland is not stable enough to drop X11.
It was stable enough for me years ago with GNOME, but had inconsistencies that had me prefer X11.
I heard Fedora dropped X11 support early because of maintenance burden. If that's the same theme removing it from KDE, it seems questionable for OSs to want the burden (OSs provide stable working software to end-users, else it's beta testing on what's supposed to be a release/non-beta OS, or at least not the best service to end-users)
FreeBSD not having systemd, featuring KDE as "the" desktop, then KDE dropping a longstanding generic solution for a systemd one sounds odd on FreeBSD's side; KDE's upstream priorities (Wayland, systemd) don't seem to align.
I felt Xfce was more of a general DE cross-OS: Traditional, themeable, most modern desktop (eye-candy) with realistic stable features (X11), and no large Wayland or systemd dependencies. I started on 14.1 with Xfce and it's worked great 14.2, .3, 15.0, and 16.0-CURRENT. I can install from memstick in <5mins and get to a visible desktop in about 10 minutes post-install.
I have history Plasma 5 and GNOME same-time around 2014 with 2-in-1 tablets and HiDPI, and GNOME handled it so much notably better I stuck with it for years. Xfce didn't have the idea touch or HiDPI support back then and GNOME had auto-rotate/brightness; Plasma 5 didn't even have an on-screen keyboard (couldn't log-in from SDDM on the 2-in-1 undocked),
yet (getting into that non-beta OS thing) Arch was happily shipping Plasma 5 fresh.
Why wasn't Xfce chosen before KDE?
Xfce recently announced Xfwl4 (Wayland compositor alternative to xfwm4):
https://alexxcons.github.io/blogpost_15.html