Option-Command-C makes a "no" sound in Finder despite being in the menu

In Finder, if you select a file, then open the Edit menu and hold the Option key, there's an option saying 'Copy File as Pathname". Next to it, it shows the keyboard shortcut is Option-Command-C.

However, if you close that menu and select a file, then try to use that keyboard shortcut, the Mac always plays the little beep sound that indicates no such keyboard shortcut exists. But...it's in the menu, and if you click the option in the menu, it works fine. So why does the keyboard shortcut not exist, if the menu says it should?

Does anyone else encounter the same issue? I'm on macOS 10.14.2, but I think I've had this issue since 10.12 or possibly even 10.11. I think Apple may have forgotten to add it and never realised it was missing.