Tell us, is it reasonable for civil aviation to ask passengers to buy insurance to deal with flight delays caused by them or the weather? Isn't this to amuse ourselves with our own money?

Insurance does not cover flight delays. It is aviation accident insurance, which is compensation for passenger casualties after a flight crash. The general coverage is 4,. The flight delay insurance you mentioned is not a compensation for you, but a refund for you because the flight did not take off and the insurance agreement was not fulfilled. So don't take it for granted that you don't understand what's going on, and learn more about it.