"Supersonic was not feasible because nations didn't allow breaking the sound barrier over populated areas." Because for some reasons, loud explosion noises cau

"Supersonic was not feasible because nations didn't allow breaking the sound barrier over populated areas." Because for some reasons, loud explosion noises causes stress in people and they don't want that. It is not a arbitary government regulation. "China's rail does not operate at enough profit " And when you add in the global cost of flying, (climate change) maybe public infrastructure does not need to generate profit, to be beneficial?