Well I believe there is foot. GTK devs ae planning to drop X11 support in gtk5 and they will start work on that after gnome 45 release so in a couple of years, all gnome apps
GTK5 might be more of an issue but so far programs barely use GTK4, let alone 5. I'm not sure GNOME applications are used much outside of GNOME. In either case i'd expect something 12to11 to work with those by then (if it doesn't already).
And TBH i'd expect there will be X compatible programs for a very long time to come.