@matthewburton It's like systems and software would not have been routinely developed to take advantage of the network lazily and opportunistically learning where endpoints are and would have had to develop the ability (protocols) to authoritatively tell the network where endpoints are.
So many of the biggest challenges in networking derive from trying to, 5 decades later, emulate putting a frame on a coax cable.
Systems need to quit assuming a common later 2 network.