I think the primary barriers to nostr’s adoption are around getting enough momentum and experience so that people will join because they friends are here and that’s where the action is. And one major issue is that nostr is considered a bitcoiner thing. Lots of people have negative opinions about bitcoin, and cryptocurrencies in general. So to get nostr to grow, there needs a way for people to join and create communities of people who aren’t interested in bitcoin and don’t want to talk to bitcoiners.
For example, in Nos, we populate our explore tab with a bunch of npubs of people we think represent a diversity of views and communities.