Really Simple Syndication (RSS) is a way for websites and podcasts to offer a feed of updated content for people. It’s a fairly standard technology but many people don’t use it.
The story of how this happened is really two stories. The first is a story about a broad vision for the web’s future that never quite came to fruition. The second is a story about how a collaborative effort to improve a popular standard devolved into one of the most contentious forks in the history of open-source software development.
Long story short (Although you should still read the long story): RSS was too complicated for non-tech users, and the internet slowly became centralized into data silos like Google and Facebook.