I don't see the problem with the systemd DOB merger, the DOB will have to be stored somewhere and systemd already has a place where user information is securely stored so they added a new field to the user database.
The alternative is not that no DOB will be stored is that it will end up stored in 20 different locations on the filesystem.
The alternative is not that no DOB will be stored is that it will end up stored in 20 different locations on the filesystem.