I have 163 current feeds covering a couple dozen topics. I use elfeed on emacs to read and manage the list. The filtering and sorting rules provided by elfeed along with bookmark management under Org-Mode/Org-Roam have solved all of my current needs.
I'm at around 100, but I don't read them directly. I feed them into an RSS aggregator with some filters to sort the feed entries into topic-specific RSS feeds, which are what I read directly.