WW2 changed the course of aviation history, as thousands of long range bombers were built, and runways were built for them all over the world.
But today, runway space is not so easy to come by near large cities, so we may see a slight shift back to amphibs. I can see that plane hauling tourists from Miami (Biscayne Bay) to islands in the Caribbean with no jet capable runways.
Or it's under heavy restrictions by the government and the unions, driving the costs up and the privacy and freedom down.
I would love to see general aviation shift back to the way things were. As it is, I would almost rather drive anywhere than fly these days.