i'm happy for you if you never have any application that hangs and ends as a zombie process but for me it happens very, very regularly (generally because of some stuff being on a network share or some hardware being plugged in an out a bit too much.. like unplugging an USB soundcard when it's being actively used, this one always causes some mess)

Not OP, but I use xkill semi regularly (like 1-2 times a week) to check whether an app is running in xwayland or natively...

xeyes can check that too, without killing the application.

aha, I just used it for a very simple reason: it was simpler for me to type "<meta+d> xkill" and point & shoot than to go through the save & exit confirm dialogs of a GUI app I was about to close

who runs js in a web browser every day in 2023.