> I need to sort stuff into categories so that you get more stuff in genres you like
I'm also trying to figure out that problem. The challenge I've seen is that RSS feeds rarely use the category field. I did notice people doing hashtags in the description field (maybe they POSSE to Mastodon or X) so I parse those out in a crawler I built [1], but theres still so much uncategorized content.
In my personal feed I aim to only subscribe to feeds I plan to read, so I hit "inbox zero" on my RSS feed every day, reading about 20% of the content. What this means is that I unsubscribe from anyone who posts too often. I think there's a negative correlation between posting frequency and my desire to read the content. People who blog every day are mostly writing uninteresting content and that will fill your feed unless you balance it out.