IMO any kind of documents cannot be used as proof of identity. Documents can be forged.

Some time ago, I encounter a project (I believe it was related to ethereum) which approach whole problem from a different angle: one identity cannot be in two places at the same time.

They focused on validation of presence at certain point of time of particular people. They build an app (or had a plan to do so), which helped organize thousands of simultaneous video-conferences between people divided into groups of five random people.

The task for people was simple: interact with all those people on your conference to make sure, that other 4-people are real, and for example they are not having another validation-conference at the same time.

Of course this is not a ideal approach, for example presence of all interested in validation people was required at the same time all over the world. The good parts is... that you didn't had to give up your privacy - you could use a wig or even had a mask.

If anyone know/remember this project, please link it.