When your account is stolen someone can create "official" documents in your name and impersonate you. There could be a system for invalidating your key after a certain date to help out with those situations.
For prominent people who actually have to worry about being impersonated they could provide their own keys.
The infrastructure could be managed by multiple groups or a singular one like the government. The point isn't to be a perfect system, it's to generate enough trust that what you're looking at is genuine and not a total fraud.
In a world where AI bots are generating fake information about everyone in the world, that kind of system could certainly be built and be useful.
For prominent people who actually have to worry about being impersonated they could provide their own keys.
The infrastructure could be managed by multiple groups or a singular one like the government. The point isn't to be a perfect system, it's to generate enough trust that what you're looking at is genuine and not a total fraud.
In a world where AI bots are generating fake information about everyone in the world, that kind of system could certainly be built and be useful.