Thank you very much for your response!
As you may guess, my article is more aggressive than what I really do. Of course, I use my phone and accept calls regularly! Sometimes, it’s much more time-efficient to throw a phone call to get a quick answer to a question, resolve a situation, and deal with human/emotional situations. So my point was not to use email for everything, but rather: 1- to think twice before calling right away, 2- to plan calls in advance as much as possible, and 3- to reduce the frequency and duration of phone calls as much as possible.
Concerning priorities, I think that you can always add a “[URGENT]” prefix to an email’s subject, when necessary. And many email clients offer the possibility to setup filters and specific notifications for this kind of emails. Incoming phone calls, on the other end, don’t display anything on the screen helping us to sense the urgency of that call.
I definitely agree with your last paragraph: We need to move to a state where we know more about the best time to use “which tool when”. :-)