In his book Changing the Subject: Art and Attention in the Internet AgeSven Birkerts shares an astute observation,

The explosion of cell phone use changed the terms of the game. That more people were able to call while not tethered to the landline meant more calls, and more calls meant a growing likelihood that those who had not gone portable would be missing calls. Along with this—again, by degrees—emerged the expectation of reachability. Responses that before could have waited for the receipt of the call or message acquired a new urgency factor. The margin of acceptable time for response began to shrink and it has not stopped shrinking—for if there is a reluctance about making an actual voice call, there is no excuse for not texting a reply. There has followed a profound (and ongoing) revision of etiquette assumptions. I am the same person in 2015 as I was in 2000—at least in terms of my calling habits—but in that interval i have grown a devil’s horns. The same hours-later or day-later response that had been perfectly acceptable is now often seen as rude. And, in a neat inversion of the former situation, the delay is now seen as a kind of preening, an assumption of exceptionality (pp. 33–34).