Comment by Sargos

Verified probably isn't the right word here. Authentic would probably work better.

I as a person have accounts on lots of apps but no real way to prove I own all of them. When you use a public key as your identifier then everyone can verify that the entity that owns Sargos on HN also owns Blah on Reddit if I want them to. Essentially you can trust that the digital entity you are interacting with is the digital entity you knew and trusted on the rest of the web in the past.

If you are using a web3 app and see vitalik.eth then you know for a fact that it's Vitalik Buterin. Unfortunately we only know this for sure because he said that is his address in public but there are many identity protocols trying to solve this problem and if you were to tie your public key to your government's identity database then you would be able to prove real world provenance.