Attention deficit disorder is probably an apt label for this phenomenon.

"This condition is sometimes called attention deficit disorder (ADD), but this is an outdated term. The term was once used to refer to someone who had trouble focusing but was not hyperactive."

Causes?

I think that this phenomenon can be generally associated with the steady increase in so-called spare time, which would require a steady increase in the standard of living and that also means a steady decline in the cost of living, the rising tide that lifts all boats (even the boats shipping the slaves).

When the difference between survival and death (of individuals and groups of individuals cooperating) depends upon focused discipline, those lacking focused discipline lose, those excelling win.

What is the effect of necessary focused discipline on creativity? I mean, can someone grasp a creative thought if their brain power is all used up on a specific necessary task at hand?

How many inventions are attributed to the Eskimo people, over and above the inventions that help catch fish and make shelter from the cold? Were those inventions invented during down time in winter? Does this line of thinking apply to this question?

What happens if the distraction that attracts the most people becomes a high intensity form of brain activity that requires the development of focused attention? Would someone invent such a thing, would it be approved or wanted? Would that reduce or increase the phenomenon of digital incapacitation? Would some people try to use such a thing to enslave mankind?