Social graph is not just the people you follow (1st degree), but also people they follow (2nd degree) and so on.

Currently Iris loads up to 2nd degree by default. There's also a tool for crawling up to 3rd degree, but it consumes a lot of bandwidth and cpu. 2nd degree was 20K users and 3rd degree 160K users in my graph, so there's plenty of diverse voices.

Optionally we could show posts from unknown users who have a nip05 (e.g. username@iris.to) from a bot-resistant provider. In a permissionless system like Nostr, we will always need to limit write access somehow or it will be filled with spam.