So we got into the sad situation that people associate peer to peer connectivity systems with having to frequently debug the entire stack and having recurrent performance or connectivity issues.
A part of the motivation for the iroh team is to change this notion by being very pragmatic and minimalistic. E.g. the use of relays vs. enlisting other peers to help with hole punching.
Originally, every machine was a directly reachable peer, but a finite supply of addresses (IPv4) forced most devices behind translation boxes (NAT) that let them dial out without ever being dialable. Once traffic had to route through the few hosts that stayed reachable, those hosts became toll booths, which is partially where the more centralized internet we actually got came from.
iroh basically patches the internet