Roughly speaking, an aircraft must fulfill a certain amount of economy (cheap, low cost to operate), safety, and performance.
If you compromise on safety, you get something that is still suitable for the military. If you don't care about economics you can participate in the space race.
But for commercial air travel, you don't have the luxury to pick just two; a competitive commercial airliner has to perform exceedingly well in all three regards.
If you're an airline using expensive aircraft you will go bankrupt. If your aircraft is too slow then your competitors will eat your lunch, and if you have a reputation of being unsafe then your customers will run away or the government will pull the plug (likely both).
IMHO affordable commercial air travel is one of the biggest marvels of 20th century engineering.
If you compromise on safety, you get something that is still suitable for the military. If you don't care about economics you can participate in the space race.
But for commercial air travel, you don't have the luxury to pick just two; a competitive commercial airliner has to perform exceedingly well in all three regards.
If you're an airline using expensive aircraft you will go bankrupt. If your aircraft is too slow then your competitors will eat your lunch, and if you have a reputation of being unsafe then your customers will run away or the government will pull the plug (likely both).
IMHO affordable commercial air travel is one of the biggest marvels of 20th century engineering.