That’s a clever start, but it has a problem. What happens when the list of age groups changes? This list is not fixed; it changes over both time and space. How do I tell the difference between a system that doesn’t support age attestation vs one that only supports age groups that I don’t know about? For example, suppose I am looking to see if the user is in the `over_13` age group, but only `/etc/age_group/adolescente` exists? What if there are multiple readable files?

Systemd’s solution is simpler and doesn’t have these edge cases. A higher level of software, such as the desktop environment, can query the user’s birth date from systemd and use their locale settings or time zone or other information to compute the correct age group.