Yes. It makes it a little more fiddly for our Government to create a PRISM-like database of our offline lives.

In my country, a lot of places use the National ID card (NIC) as a means of security. For example at a lot of office buildings or at "extra-secure" neighbourhoods (especially where military personnel live), they ask you to leave your NIC (or a copy of it) at the gate. So in case of an incident, they would have a record of who checked in and stuff.

Another security use case is in Banks. Since handwritten signatures are weak security, they usually ask you to attach a copy of your NIC when cashing/depositing cheques so they can trace the guy later in case of unlawful activity.

Yes yes, all above measures have loopholes but it's still security. I m just saying that ID cards aren't all bad. they have their uses.

My bank won't let me take money out without either my debit card or photo ID, so that's kinda moot.

A number of other things can be used as collateral, including, where absolutely necessary, a passport or drivers license.

There's no killer app, so to speak, for a national ID system that isn't solved today by voluntary means.

So each govt body seems to have it's own persona of you. While I understand that this in some way supports privacy against the govt, but it just makes me wonder how they handle certain issues. off the top of my head:

Aren't your passport or driving license connected to your other persona's?

If someone gets arrested, wouldn't that be tied to some existing Primary Key? How else would you know past criminal records of a person?

Do all the bodies simply work on "Foreign Keys" since there is no central Primary Key? And if all records have each other's foreign keys, doesn't that defeat the purpose?

It sort of defeats the purpose, but because these are across organisational boundaries, it makes it rather more difficult for anyone to actually do anything with those links, and more expensive. A national ID system leads to a national database where much of this data would be much more accessible to the entire Government.