Why can’t you use audio-frequency electromagnetic waves for radio communication?

Since they have low power and after radiation they decay very quickly. Vibrations in audio frequency are relatively slow vibrations. Almost no sound frequency electromagnetic waves are emitted. To transmit such waves over long distances, it is first necessary to convert them into high-frequency oscillations, which is a modulation process, as a result of which a low-frequency signal is superimposed on a high-frequency one.