Last year I was using KDE on Alpine and frequently when trying to close smaller pop-up windows the whole shell would crash into a no-shell black screen. Earlier this year, the crash would still happen, but most of the shell, sans wallpaper like in your case, would respawn. So KDE have actually improved in this department.

When I switched to OpenBSD this year, I told to myself: KDE? Likely never again. Likely still too unstable.