Comment by Matumio

Other people do, though (not mine): https://github.com/facundoolano/feedi

I'm not using that one yet, but I very much like their idea to highlight infrequent sources. If I hand-added the feeds, I feel they should by default have at least an equal chance of me noticing a post in them, without clicking through all the feeds.

I also like the idea of subscribing to everything and then privately filtering the for special-interest keywords. I'm not doing that currently, but I subscribe via RSS to some searches or tags. E.g. here via hnapp.com, or on StackOverflow you can subscribe to tags, or the RSS feed of low-traffic subreddits.