You obviously don't work with customers.
I do, actually. Well, they're more partners than customers, since we give them our code and they sell it. But, yes, I have a lot of meetings with outside parties. We convince about half of them to join our Hangouts from their laptops, the others we add to the meeting via phone. Outside of meetings, we communicate entirely via e-mail. Voicemail is still irrelevant.
At IBM, my role was entirely customer-facing. Voicemail was still fairly rare, though teleconferences were the norm. Most communication was, again, via e-mail or face to face.