[Sayrus]

Assuming you want ID verification, why would you need a blockchain? Your identity is deeply linked to who you are and we have identity documents and trusted entities to provide them. These entities can absolutely act as a third-party to verify who you are. This can happen with several different parameters: whether your identity is provided to the site you are using, whether the site your are using is known to your identity provider, whether identities across sites are identical or only linkable by the trusted party. But in all those examples (that are currently implemented by some countries), blockchain is not a requirement.

Assuming you don't want actual ID verification, the choices are even larger but with different trade-offs.

[drumdance]

In theory yes, in practice it requires lots of different government services to get on the same page. How do you verify a state ID? Usually the DMV. Have they released an API endpoint for that? Almost certainly no. What if instead you're using a passport? Then the federal government needs to do it. What if your passport is from a country with weak government that doesn't have a lot of capacity?

And of course governments attract hackers because they tend to not be up to date on security best practices.

A single abstraction layer on blockchains allows more developers and security experts to contribute and innovate.