It's almost as if the development of technology and politics are interrelated. Half the cost of building US airports were subsidized by the government when they added them.
Path of development and real estate prices are related to accessibility. Most of the US is not accessible, there are an equal number of paved and unpaved roads in miles. Consider receiving mail in a rural area where it's going to be 3-5 days for an amazon prime package and the closest store is 30+ miles. If you randomly sample locations in the US you'll find that is actually really common, it's just not experienced by many people. Rail networks aren't about going on vacation, it's about developing real national infrastructure that creates efficiencies that boost multiple parts of the economy.
No, not possible at all.
Intentional investments in R&D led to more fuel-efficient and long-range aircraft technology such as the B787 and A350 which allowed new point-to-point routes between cities that were never before possible, abandoning the hub-and-spoke model of the past.
Like Auckland-NYC nonstop.
Imagine if they had to build rails between those two.
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?
China's rail does not operate at enough profit to pay off the original construction let alone for future maintenance.
What you are referring to for flight is government policy around it, not the capabilities of flight. Supersonic was not feasible because nations didn't allow breaking the sound barrier over populated areas. Again government restriction, not a limit of the technology. Air flight does not require eminent domaining peoples land to add new destination. In fact new air travel destinations/destination changes/capacity gain growth over the last 30 years occurred in ways that rail never could.