Your wife or mother calls you or video calls you and says to meet her somewhere, or to send money, or to pick up groceries or whatever. Does it not matter that it wasn't her? Could it be someone trying to manipulate you into going somewhere, to be robbed or whatever? At any rate, you'll need to verify that information came from the source you trust before you act on it, and that verification has a cost.

The damage is to the trust we have in our communication media. The conclusion here is that every person is trivial to impersonate; that's the damage.