I hate seeing things like this:
When I see a blanking plate in the middle of a bunch of other faceplates, I don’t think “what a neat job they’ve done.” I think “what have those sons of Hades hidden behind that?”
I tend to ignore it unless I happen to be passing with a screwdriver. Then, one day, curiosity will get the better of me.
At which point, I will find something like this, and promptly suffer a brain aneurysm.
As you may have deduced from the outstanding labelling used by the installer, I have no idea where this cable goes.