The problem with that is that it leaks too much information to anyone seeing it — this is bad if it needs to be used with any party you might not trust (or not trust their security). Serbia (former Yugoslavia) already does something similar since 1970s, and your Unique Citizen Number (JMBG) is derived from your date of birth and county of issuance (usually birth county) and sex at birth, a couple of digits and a single digit checksum.
Ideally, government could issue a cryptographically signed ID, so anyone with access to countries' public key can verify authenticity (with revocation mechanism built-in for both individual keys and all keys signed with one government — this is where it gets tricky). Obviously, governments become new CAs, and people in them can provide fakes when they want if they are corrupt, but anyone can easily validate it.
It says the state assigns "A body" a number.
-vs-
The state is made up of us as individuals.
So while the serial keyfield is a data engineers dream, politically I'd welcome something more personal.
Time of birth/parents and other identifying information is on our birth certificates in the UK. Concatenate some of that.
I could be.
DavidAndrewEvans-01011980-0036-MRI-JeanDavis-AlexEvans
Name-DOB-TOB-LocationCode-Parent(s)
Location of Birth like an airport code - MRI (Manchester Royal Infirmary), Parent(s)... i mean we can use their birthdates too.
I actually quite like the idea of it. It seems intrinsically validating to a person to identify them in this way.