A large IRC network is a mesh of servers (relays) that all share the same content. They are run by multiple entities because they are multiple individual servers (relays in our example). In this example Nostr is the IRC network, and relays are its servers.

Large IRC network do have central governance, which is usually made up of all individual server operators and used to decide on network-level things, like services, which other servers should be added, etc.

For clarity, I want Nostr to be like those large IRC networks, where all servers (relays) share the same data and all channels (communities) are unaffected by the actions of a single server.