It is actually a requirement under mat regulatory systems. It might seem excessive, but it gets the point across. A pan would seem to be adequate, but often the failure to communicate issues has led to bad days. Much of the world will only achieve curiosity from a Pan call.
Unfortunately true.
During a type rating course on a modern twin we were pulled up for not declaring MAYDAY after an engine failure. His logic being we don’t know why the failure occurred and we are down to 1 engine.