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

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.