That's specific to X11. It also wasn't always enabled for security reasons (breaking out of a locked screen). Now with Wayland there's no standard.

It's turned off by default in a lot of distros these days but it can be turned back on. It used to be that editing /etc/X11/xorg.conf was recommended but because file inclusions are a thing these days, it makes more sense to create a new file /etc/X11/xorg.conf.d/enable-killing-xserver.conf:

Section "ServerFlags"
        Option "DontZap" "false"
EndSection

Section "InputClass"
        Identifier                       "Keyboard Defaults"
        MatchIsKeyboard        "yes"
        Option                           "XkbOptions" "terminate:ctrl_alt_bksp"
EndSection

Then restart the X server (which, these days, is pretty much a reboot). Or, going through the x.org documentation archives, it looks like you could dispense with the config files and run setxkbmap -option "terminate:ctrl_alt_bksp" in a terminal session and that'll do the same thing.

Additionally, it terminated all gui processes. Which the windows shortcut mentioned in the question doesn't.

That doesn't work for Wayland and I'm unsure which one Zorin uses

That doesn't restart anything. That kills the X11 server.

It may or may not restart depending on system settings.

That is not an equivalent.

On Linux, if a graphical app does not crash from this, that is a rare exception.
On windows, if a graphical app crashes from that, that is an exception.

That is just the key to kill the X server. It does not restart anything.

I was thinking of that when I read this and was like. windows has something like this???