What? Not at all. RSS is a product category. Many RSS feeds are, if you look into them, Atom. Your RSS reader just doesn't bother to tell you, because why would you care?

Try putting a Betamax tape into a VHS VCR and see if you can watch it.

Atom is a response to not wanting to support backwards compatibility like RSS does in order to improve things. https://web.archive.org/web/20080216234454/http://www.sixapa... It's explicitly a different thing.

This is like pointing at the monitor of a desktop computer and saying, "that's the computer". It is effective to communicate with people who aren't interested in computers, but it's also not true and the distinction does have important consequences for behavior. Atom is not RSS even if some feed readers support both and most people don't know what feeds are.

And because of that, and the early popularity and widespread adoption of RSS, the better format (atom) isn't used nearly as much. And calls to increase use of betamax/atom generally went and go unheeded.