You don't need key signing parties to bind pubkeys to their owners. What you need are pubkeys that have an association with their owners which remains stable over the long term. That's because, given enough time, you'll always have plenty of opportunity to observe all kinds of cues and signals that will tell you who is behind a pubkey, at least to the extent to which the owner wants to reveal that information to you. For example, over time you'll be able to tell whether the owner is a bot or a human, what their interests are, their writing style, what communities they are part of etc. And if they want you to know their name or other "personally identifiable information," there will be almost always be easy mechanisms by which they can convince you that they are who they say they are. It seems very unlilely that AI's ability to impersonate will change this, either now or in the future.

The pubkey @npub10ukg...x0x9 has never ever signed a single Nostr event. Yet that pubkey has recently gained its first real-life follower. I admittedly don't know whether they'll decide to stick around or not. But it's a small milestone in the (very early) history of Inkan.