I’m not sure that XWayland is the actual problem in crashes though.
While it’s the one shown in the stack-traces the very same problem is also shown when mutter crashes first…
However 3.34 will hopefully have XWayland on-demand, causing this not to be a problem anymore, if ever was.
In any case, the problem is that in X11 the shell can crash but applications won’t, so there’s a very low risk of loosing the current job, which is not the case for Wayland (yet).
That said, Wayland can be choosen at startup, so I don’t see an urgency in default switch.