I think that is a good thing. For "syncing across devices" to be a server-side feature of RSS, that would require that the server be keeping track of who I am a

I think that is a good thing. For "syncing across devices" to be a server-side feature of RSS, that would require that the server be keeping track of who I am and what I have read. The way the RSS protocol is, it is stateless and may be completely anonymous. Keeping track of the state is (and should be) the application's job.