Since you mentioned steel and airplanes, I need to ask what were the disastrous effects of the "plateau". While airplanes reached the physical limits in the 70

Since you mentioned steel and airplanes, I need to ask what were the disastrous effects of the "plateau". While airplanes reached the physical limits in the 70s, there were still many revolutions ahead, for example the low cost revolution that brought air-flight to the masses.