An interesting thing is IE had similar RSS support for rendering RSS feeds, configurable subscription options for them, and RSS feed-driven favorites folders. (Of course, none of that has made it into Edge. Yet?)
Perhaps more interesting was that IE had a platform API for its RSS store. It supported using the same Background Intelligent Transfer Service (BITS) that Windows Update and other systems use for background downloading things during "quiet" periods on the machine to update the feeds. That RSS store provided a lot of what you needed for a good RSS reader application, though few reader applications took advantage to my knowledge. (I recall having part of a hand-crafted one at one point.) Outlook used to use this RSS store for its RSS support (thus sharing its feeds with IE), and the shutdown of IE's RSS support may be part of why Outlook's RSS support hasn't really worked that well in the last several versions.