Zeronet maintain the site content by each users as shared folder, hence audience only need to sync the current state, not the entire history. Sounds more efficient than SSB
There's no site, so I don't know how this is related? SSB is a peer to peer protocol, and (aside from the UIs of most desktop implementations being electron) doesn't use webtech.
I suppose people use SSB mainly for social network, so each "site" can be the wall of the users, with posts and comments submitted by the users or their friends.
But you're right, SSB is more broad as a generic p2p message protocol (and zeronet is a generic p2p site protocol)
