A digital identity that lives on a smartphone.

A digital identity that lives on a smartphone.
My son is 7 and doesn't have one.
Oma is 79 and doesn't want one.
The neighbour has one, but the battery has been dead since yesterday.
All three stand in front of the same door. Cinema, sports club, library, doctor's office. The door asks: "Are
you old enough?" or "Are you who you say you are?"
Who stays outside?
And whose fault is that: the person's, or the door's?