Hmm, this really looks more of a relay network for sale, kinda like steam p2p. The only real use-case I see for this is for exactly that, connecting two or more players where one of the players is the host.
Seems like it'll be a hard sell since steam is already so dominant and enterprise is dominated by tailscale... I see the proposal for being able to work with many different networks from different companies at the same time, but it's a pretty rare usecase and nothing some iptables can't solve.
I can see the argument for chat in heavily censored regions of the world, but not sure if there's any advantages that iroh can offer over other solutions.
Market fit will be hard to find, but best of luck.
Steam sockets and CloudFlare's UDP forwarding really are different though. They provide ddos protection as well as route optimization due to lots of points of presence.
Here there seems to be no mention of ddos mitigation or shorter routes due to infrastructure. Yes you need a key to connect but your iroh relay server can still be attacked. I suppose you could roll your own distributed anycast system for this.