[vidarh]

There are plenty of Wayland compositors that supports X backends, so app support for X is moot because 1) most of the apps I run are my own - the only thing I really depend on is browsers, and 2) once Chrome and Firefox abandons X entirely, and no other browsers based on their engines supports X, there are options to run them with a Wayland compositor with an X backend in "kiosk mode" that basically gives them a single window just like before.

So that leaves how long I will have a working X server, and frankly I suspect I'll have ended up writing a display server years before that becomes an issue (whether that'll be X or Wayland or a mix, who knows, but I doubt I'll be able to resist very long).

It's just not a concern that's anywhere near the top of my list (or the top 100 of my list)

[Vecr]

You can run an X window manager on a Wayland compositor, as you said the problem is when programs stop running on X at all.

[vidarh]

Well, no, even that isn't a problem, because you can run a Wayland compositor on X too.

E.g. I tested, and Firefox runs fine in Weston in kiosk mode w/X as the backend.

So even when Firefox drops X, it will still run on X as long as a single compositor with an X backend is still running.

[Vecr]

Great, my Firefox on Weston on i3 on XWayland on Gamescope idea is a go (when I get around to implementing it).

[vidarh]

The funny thing is in theory it might work reasonably well, as Weston at least uses the DRI3 extension to get the underlying X server to just pass the DRI filedescriptors up, so if the rest also supports it you'd in theory just get a game of passing the fds through multiple layers and then the client doing direct rendering via shared memory. Though in practice there's of course plenty of things that might go wrong.