Temporary solution: 

As much as I hate to say this, but, maybe client's could offer first timers "content profiles" where there are pre-set/curated mute-words that allow very simple feed curation like this. It would allow clients to easily teach users how to build their own feeds. Something like a +/- next to some words. A first-time tutorial would allow them to enable/disable said profiles.  

 i guess as part of the onboarding process you could have a user select topics that they definitely aren't interested in and don't want to see those topics.

https://i.imgflip.com/98kge8.jpg
 

 YES PLEASE 

 As long as it's really easy to turn it off. I say temporary because it only matters when the amount of topics are small. If you mute bitcoin, GMs, and nostr dev chat, this place is pretty quiet and people may also want to leave.