This is very simplistic and ignores all the trade offs that got us to where we are today. For one example what if, instead of depegging from gold and creating the petrodollar which was then enforced by the MIC, what if nuclear power had proliferated everywhere? What if the MIC was just a nuclear MAD race? What would the world look like with 5 decades of infrastructure build out, R&D, education advances, a skilled nuclear workforce etc? You think we’d only have got to electric cars in the 2010s? You think we’d have found our way to cloud computing of today in that environment? Wars and conflicts probably would have looked different.. Everything would really, definitely including flight. In any of these thought experiments you’re forced to ignore all of the trade offs that led to the point in time of the thought experiment. If the basis of the argument was “we’ve had abundant nuclear power around the world for 30-50 years” and flying cars is still impractical it’s a very different to flying cars being impractical in the current reality.