Engineers don't build the cheapest bridge that just barely won't fail. They build the cheapest bridge that satisfies thousands of pages of regulatory requirements maintained and enforced by dozens of different government entities. Those regulations range from safety, to aesthetic, to environmental, to economic, to arcane.
Left to their own devices, engineers would build the cheapest bridge they could sell that hopefully won't collapse. And no care for the impact on any stakeholder other than the one paying them.
> Left to their own devices, engineers would build the cheapest bridge they could sell that hopefully won't collapse.
I don't know any real (i.e. non-software) engineers, but I would love to ask them whether what you said is true. For years now, I've been convinced that we should've stuck with calling ourselves "software developers", rather than trying to crib the respectability of engineering without understanding what makes that discipline respectable.
Our toxic little industry would benefit a lot from looking at other fields, like medicine, and taking steps to become more responsible for the outcomes of our work.