RSS also doesn't work very well in pure client-side development, whereas the same data structure in JSON is easy in pretty much any context. Say, for example,

RSS also doesn't work very well in pure client-side development, whereas the same data structure in JSON is easy in pretty much any context. Say, for example, I want to show a list of items from a 3rd party in a sidebar on my site. With a few lines of jQuery or other similar lib, I can do that no problem. Maybe RSS, just like XML-RPC which was still much better than SOAP but has fallen by the wayside in favour of REST + JSON, can be supplanted in the same way.