PGP is a good solution, and in general the crypto space has the right idea in my opinion. I like the idea of using cryptographic key pairs to sign messages and prove identity, but the learning curve makes it impractical for general use.
The best place to start is owning a domain you control, at least that way you can manage your own facade.
In general, if you want people to be able to use cryptographic signatures to prove their identity, they are going to have to know what those things are and how they work. Since this is an entirely new thing in the world there is no existing culture to map it to. The problem is not specific to any particular technology.
This would be an excellent topic for new curriculum for the schools. Some ideas need to be generally known to be beneficial.
In some cases providing identity is a good idea. In a web full of advertising it is mostly not.
My domain is completely detached from my online identities, even for private and professional development to a large degree.
Many domains are pretty cheap though, not much more expensive than some mail services. Of course they don't come with respective keys for which you might have to pay extra.
PGP is a good solution, and in general the crypto space has the right idea in my opinion. I like the idea of using cryptographic key pairs to sign messages and prove identity, but the learning curve makes it impractical for general use.
The best place to start is owning a domain you control, at least that way you can manage your own facade.