Do Nostr relays communicate with each other? It seems to me that they don't.
Discussion
So to make Nostr bit usable, one would have to write relay that behaves as both relay and client.
there are things like blastr, but outbox model made it more or less deprecated.
Also you can write/read to as many relays as you want.
some clients (primal i think) even use their own cashing server which reads from many other relays. That's probably something you like.
I think it's stupid and relays can do everything the cashing server does.
outbox is the king
Some relay implementations have a "negentropy" feature by which they attempt to pull in events from other relays over time.