Agreed. A problem I think nostr shares with other "social" platforms is that you can't follow someone without seeing everything they post. For some people, that's fine and awesome but sometimes I want to follow someone for their posts about certain topics (eg Minecraft, football) and not others (eg Politics, bitcoin).

I think there's room here for some form of client-side filtering rather than something at the relay level. A simple filter could be based on hashtags. Something more advanced might use a LLM to detect the topic which comes closer to solving both the "sender didn't set a topic" and "spam post isn't related to the stated topic" problems.