Yeah, this is a common problem. People often give advice thinking it's just a matter of not being able to find the topics, or laziness in trying to find the topics. Maybe if you follow more people it will help your feed? When in reality there just aren't many or sometimes any notes about lots of topics. Never mind a bustling group of people speaking meaningfully about it. And yes, not even talking about esoteric interests lol.

Nostr in various (often unintentional?) ways incestivises and cements a dominant (mono)topic / community.