The only tech that changes the game more radically than infra 5 is infra 1. The REAL answer is infra 1, but there's no country that can't reach that very quickly, so it's not easily noticeable.
I think that any poll you make including infra 5 will be pretty uninteresting. I think a better poll would be "besides infra 5, what is the most important tech advance?"
I think that any poll you make including infra 5 will be pretty uninteresting. I think a better poll would be "besides infra 5, what is the most important tech advance?"