One thing that would make Nostr more usable, apart from being able to find other people based on their interests, would be having a way to categorize the people you follow in various ways. At the moment you just have one massive feed. While that might make sense for a user base that is only interested in cryptocurrencies, so you can assume that that's what they're all talking about, in the real world you have different groups of friends associated with different interests, and what they are talking about makes sense only in respect of the purpose of the group.

If Nostr is to grow it has to be more accessible to people who have focuses other than bitcoin, and indeed have many different types of discussion they want to be having with different people, in the context of those discussions. It needs to facilitate that.