rss-filter removes noise from any RSS or Atom feed, just like an email filter.
Give it a feed URL and it'll generate a new one for you without all the stuff you don't care about. For example, you might be tired of reading Hacker News articles about AI. Or if you don't like opinion pieces, you could filter out New York Times articles whose links contain /opinion/. Use regular expressions for advanced pattern matching.
If you ever want to modify a feed created via rss-filter, you can just paste its URL back into rss-filter's URL box! The previously configured values will prepopulate into the remaining inputs for you to edit further.
rss-filter is 100% free to use. Hosting it costs me like $10 a year. Enjoy!