Same , wish there was a directory of rss .
In past it was googles task to provide quality sources when searching and google excelled at this but somehow google is failing at this now.
There are people like me, who write blogs that routinely include links posts. Subscribe to those blogs, check out the stories that interest you, and subscribe to those sites in turn. I have a couple hundred sites in NetNewsWire.
The point is, if you upvote this link on LinkLonk (https://linklonk.com/item/481037215144673280), you automatically get subscribed to all of these feeds. This is a way to discover new feeds through content you liked.
Now, being connected to hundreds or thousands of feeds might seem crazy. But we have a solution to that which also relies on what content you "liked". LinkLonk knows how often you liked content from each feed you are connected to (which is essentially the signal-to-noise ratio). So it ranks new content based on that. If you like 50% of posts from https://simonwillison.net/atom/everything/ then new posts from Simon Willison will be shown above other links from, say, https://lobste.rs/rss.
The more you like - the better the ranking of fresh content becomes.
In this world you don't have to actively manage which feeds you are subscribed to or not. You only rate content.