They are, but there is no need for us to all be at the same one;
Be it here, or there, we recognize each-others identities and data-formats and the query language with those servers is the same. This means we can use interoperable interfaces (clients), and because on the internet, time and space collapsed; with the same ease with which the entire world can visit the same location, they could also just visit the place where they need to be at that particular moment.
Websites+RSS is really close to Nostr. At some point i had my RSS setup with all the newssites and what-not, but the rest of the internet decided to move in a different direction, time to steer is back