> Government provided digital IDs
Oh man, that sounds like a terrible idea privacy wise. Every website would make use of it to track it's user.
The german gov ids actually have a way to issue pseudonymous tokens where websites can only see that you are the same person as last time.
You can't make 2 accounts on the same site if sich things are unwanted.
You can't link accounts across providers.
How it works under the hood? No specific idea. I wonder if its sound.
For the rest you can do weird stuff that doesn't work on nerds.