I think people were much more willing to risk their lives (and risk other people’s lives) in the past than they are today. We have elevated the role of the individual. Younger generations are all “me” generations. (I’m not saying that’s a bad thing, it’s true for me as well.)
Case in point is the Western expectation of acceptable losses due to warfare. If we needed to pull off another D Day invasion, I don’t think we could. Generation Z is not signing up to die in tens of thousands and I don’t blame them. The casualty rates that were once seen as the normal cost of war and industry are totally unacceptable today.