You probably know somebody who knows somebody who knows them, we're just not presently engineering for that fact to matter.

The most famous attempt at a web of trust was PGP, but it just attempted to bind a public key to a name. That's too generic. Only privacy nerds are actually going to have a key signing party if that's all they get out of it.

I think that it'll go better if the we're attesting about common interests. Like, go to the event because you're enthusiastic about games, end up with some public keys as a side effect.

It'll be hard if you're the only person you know with a particular interest and it's impractical to travel to wherever people with that interest gather. Then you'll have to take a gamble on some internet handle you've never met. But really that's just falling back to the dubiously trustworthy web we currently have.