> he problem is that the software stack makes tons of round-trip requests
Latency matters because of all of those round-trip requests. Each individual request incurs at least 2x the network latency value (one network latency trip out to the server, another network latency trip back). If browsers did not try to run parallel requests, then all those round trips would sum up to a substantial overall delay.
That describes zero browsers. And "it's not loading parallel enough" is very much a software stack problem and not a network problem.
We could shove full pages over the wire in 200ms if we tried harder.
Well then, since it's a physical impossibility to do away with them, we'd better start working on improving the speed of light.