I understand your premise, but I think the missing part of the cost function here, especially when it comes to safety, is the price of a human life. The US government has actually quantified it, and I think when we account for that it’s probably worth it. Though where exactly that money would come from is a problem.

Similarly, we know certain preventative medical treatments are costly but save money for the system as a whole when universally applied, yet we still don’t do it.