If there was a way to distinguish 2:2 from 3:1, it would affect how networked games played out. It would affect how ordering violations were resolved, which is pretty important in games ("Did I block before that punch landed?"). It so happens that the cases can't be distinguished, so it "doesn't matter".
As an analogy, what would the world be like if the speed of light wasn't invariant with respect to velocity? It happens to "not matter" because the speed of light is invariant in that way, but it's still an interesting question.
It certainly matters to adjudication. But perhaps the question players care about is not quite, "Did I block before that punch landed?" (a very important question), but, "I just blocked, but he hit me for some reason anyway."
That is to say, players get upset (1) if something seems to violate their own worldview, due to adjudication. Naively, we could solve that case by running the timesteps of the simulation slower than the greatest latency (or more accurately, when heartbeats from all players have been received for a given timestep). That would introduce us to another reason players get upset: (2) if the game is really laggy.
I'm glad you bring up relativity as an example. The best method games have for improving the real-time illusion is locality.
As an analogy, what would the world be like if the speed of light wasn't invariant with respect to velocity? It happens to "not matter" because the speed of light is invariant in that way, but it's still an interesting question.