And so is X11. We are heading for a dual stack desktops. There are tons of expensive applications that target Linux _because_ of X11 and they will rather force users to switch OSes than get rewritten.
Pretty much any app that uses a toolkit won't need to be rewritten. Most of them just need small changes, or even no changes.
Those that are written to use Xlib directly, sure, they'll take some work (though rewritten? doubtful). If their maintainers don't want to do that, they'll still run under Xwayland.
These apps were written for X11 and NFS, so they can run on any node in a cluster. The were typically deployed on commercial UNIX systems and ported to Linux when Sun went belly up. In practice, I don't think porting them again will be needed. It is enough to qualify a different distribution if Redhat chose to exit the workstation market. There are already companies like NoMachine that keep X11 running.
It is not even about the access (people usually use nx or even vnc for that). It is about having a system that can work as a part of a cluster (network filesystem, X11), with all base GUI utilities (terminals, file managers, browsers, pdf viewers) supporting that.
> And so is X11. We are heading for a dual stack desktops.
IMO, we're heading for "X11 over Wayland" desktops, in which the only X11 implementation is Xwayland. These expensive applications which target X11 will keep working, through that compatibility layer.
There are other Unix systems but by far the easiest solution is simply making sure all installed apps can still behave as X11 clients. Wayland or Xwayland is not really any issue. Few people use Xorg directly, as the new deployments usually require some form of a remote access.
