Email would not have been Harry Truman's thing. Email is a useful tool, but also one that's borderline abusive when it's used to pass the buck: Here, do this. Hey! Where's that ___ and ___ you promised? Regards. The Send button is the Internet's semi-automatic weapon: press it and presto, Inboxes are filled full of, well, something.
Picking up the phone ( or even sending a text ) requires more thought, more time, more responsibility, more empathy and more skin in the game, even if just a skosh.
Life in the contemporary workaday world is often an exercise in not spreading yourself too thin. We're all busy. But what is it that suffers when we sacrifice our humanity to empty boxes looking for check marks?