I agree that the opening post question as phrased is fundamentally flawed.
“Efficiency” is defined there, as “cost, and time taken to complete.” That’s a common, but defective way to measure efficiency. It ignores, or at least obscures, the question of whether the completed task, actually fulfills the full list of goals it was intended to take care of. And usually, it ignores how truly tricky the subject of “costs” has always been.
I personally would say that American civil engineering at least has NEVER been more truly efficient than it is now. ESPECIALLY because of the POSITIVE contribution of MOST of the modern regulations. Those regulations are designed, in addition to making the workplace itself more safe, to see too it that whatever IS built, actually performs as needed, does so for a much longer time than previous “efficient” constructions, and more important, sees to it that the particular effort in progress, isn’t going to cause an additional set of new problems going forward.
As some have hinted above, if you play a coy game with your definition of “costs,” shutting down an entire city while a bridge is being built, so that the bridge can be constructed in record time, only looks great on the cost ledger, if you ignore the huge disruption of all commerce, and the tremendous rise in cost of living that everyone in the city suffers as a result.
This kind of manipulation of costs and misunderstanding of real efficiency, is at the core of a very VERY bad fad political trick being played on the United States for the last half century. Pretending that all regulations are the result of petty emotional wimpiness, or even actual intentional sabotage of American Productivity, has become so common, that many who delude themselves that it’s true, now simply roll their eyes at each other when anything related to thinking more carefully about ALL factors in a situation, and then cheerfully bash their way forward with whatever they want to get for themselves.
