How does that work in the context of the whole system where I need to link a key pair to a person? If I know you in real life we can check key fingerprints or something (GPG suggests statistically nobody will) but otherwise I have to trust a third-party who says that the Bob I want to talk to has keys X, Y, and Z.
If you don’t do that, as soon as it becomes popular enough to attract scammers you’re going to have Mallory publishing keys with Bob’s name on them and a million random people who have incredible financial opportunities for you. Most of the decentralized systems shift that problem to another system like email or DNS, Facebook/Twitter/GitHub/etc. at which point it’s worth asking whether there’s still value in decentralization at that point.