The uncertain possible futures of Unix graphical desktops
Once upon a time, the future of Unix desktops looked fairly straightforward. Everyone ran on X, so the major threat to cross-Unix portability in major desktops was the use of Linux only APIs, which became especially D-Bus and systemd related things. Unix desktops that were less attached to tight integration with the Linux environment would probably stay easily available on FreeBSD, OpenBSD, and so on.
What happened to this nice simple vision was Wayland becoming the future of (Linux) graphics. Linux is the primary target of KDE and especially Gnome, so Wayland being the future on Linux has gotten developers for Gnome to start moving toward a Wayland-only vision. Wayland is unapologetically not cross-platform the way X was, which leaves other Unixes with a problem and creates a number of possible future for Unix desktops.