FOSS RSS Readers with Content Surfacing

Does anybody have any recommendations for FOSS RSS readers with actual content surfacing features? So many RSS feeds are full of junk (this is particularly a problem with feeds with wildly disparate posting frequencies) and I've always felt they'd be a lot more useful if people were putting more effort into a modern way to sort through extremely dense feeds.

EDIT: Actually just stumbled on one for mobile. Check out Nunti on android (https://gitlab.com/ondrejfoltyn/nunti)