I think Windows does some things well, that are just worse in KDE
Ctrl+Alt+Delete, Taskmanager is actually privileged and can force close running apps. On KDE the same apps exist but they are not privileged enough. EDIT: of course it is privileged, but it doesnt even open if the “Desktop” hangs. There seems to be no privilege isolation, nothing left as security space for these tasks.
The UI is more stable, the bars dont weirdly load, App Windows just open in full size and not fly around. When an app crashes I can still use the cursor (often)
The Rest is crap, like everything. Updates are horrible and intrusive without a single reason. Immutable updates are so much better, regular Linux Distros probably cant compare regarding security.