@abliss Great question. I'd love to see such a directory or list, too. Not exactly RSS-based, but Kicks Condor has been sharing links to others that curate content / build directories, and generally talking about the "digital gardens" movement: https://www.kickscondor.com/
Personally, I follow the shared links from my old time college friend Chema, who aligns pretty well with my interests: https://rinzewind.org/shared.xml