I can't think of anything, other than updating PiHole and trying to do some of the encrypted DNS stuff that requires me to use the CLI. Install on a supported OS is braindead simple:
Code:
curl -sSL https://install.pi-hole.net | bash
Updating is also easy:
Pihole update can include the restarting the lighttpd process which would kill the update process if run via the UI.
If that's too 'Orwellian' then I don't really know what to say. GUI's have a hard time covering all the options enterprise level switches present, with the possible exception of wireless (looking at you, Cisco WLC command syntax). I have yet to encounter a GUI on an enterprise switch from Cisco, Juniper, Brocade, or HP, where I couldn't do the same thing faster, more easily, and more accurately, from the CLI.