There’s a separate issue of verifying and identity proofing wallets.
But I think blockchain actually helps solve the problem with pgp of trusting unknown identities and key exchange. Currently if a document is pgp signed by John Doe, I’ve got to figure out if it’s really John Doe and that’s a bit of work if I don’t already have John’s public key.
[0] https://ycharts.com/indicators/ethereum_average_transaction_...