It's not really like this tho is it? Yes we have all these groups, but would you say there is a lively community of skydivers, talking about skydiving in-depth, consistently and meaningfully?
Discussion
The overall nostr vibe seems to be bitcointwitter chatroom -style posts and not topic posts. That is the main impression it gives too, which is why most people complain about this.
I do think Homesteading and Meshtastic are way ahead of other other subcultures/circles. I think you could invite someone interested in either of those and they would find a fair amount here in terms of community and conversations.
I don't think you could say the same for skydiving, or many many other topics.