More people eager to speak with more other people more often. Too often.
Add to this fewer secretaries, and you get lots of phone calls going nowhere. Frustration with this unhappy situation led to the invention and propagation of voicemail — and fewer secretaries, I guess.
Today, we have email services, of course, and they can reply to emails on their own even:
›› Let AIM Mail reply to incoming emails while you're away.

Would Zeus, head of gods, send lightning into a thin and spindly myrtle or the grand and knotty oak?
It is a question along these lines that had Shakespeare coin the term gnarled — for a beautiful old, majestic and, well, gnarled oak:
›› The tree grows more beautiful with every gnarl, and so do your emails. (Outlook, Outlook Express)