I use NetNewsWire on my iPad and Feeder on my Android phone to read RSS feeds from multiple sites (including Lemmy and Kbin). I also use it to monitor niche sub-reddits so I can give Reddit as little traffic as possible.
I guess it was inevitable that Reddit would know many are doing this and begin to kill RSS feeds. I’ve noticed the past few days that my feeds were not being updated very often, if at all, even though the feed appears to still be there.
This started a few weeks ago, apparently:
https://www.reddit.com/r/bugs/comments/14z44nw/rss_feeds_are_broken_for_most_subreddits/
Really Simple Syndication is a format that allows a program or user to download a bunch of stuff as a simple list of titles, content and tags. RSS readers can also combine different sources into one feed, so you can grab articles from many different RSS capable sites and combine them into one cohesive list.