But unless you have a body like a kangaroo, the amount of energy needed to hop regularly when your mass is above a certain amount will be more than you can afford. Try hopping to work tomorrow instead of walking and see how long you can manage it.
In fact, there are several reasons, the major one being that telephones completely remove any visual cues from the process of communication. Not only do we read emotional content off the posture of a speaker’s body and face, but language comprehension is aided by a subtle form of lip reading.