The irony of this failure is that the US civil war was the first true economy-vs-economy conflict, with mechanized rail changing the scope and nature of conflict (while actual combat was still with napoleonic-class cannon, cavalry charge and the like). European powers mostly ignored this conflict, and so it took a while for them to understand what WWI was really about. Then the US took this lesson to heart, and didn't recognize that the only alternative for their adversaries was asymmetrical combat...a full circle as that was the approach the US had taken in its own war of liberation from a superpower.
The other, even more meaningful point about industrialized warfare is that it has its own Taylorist logic. For the European theatre, they built an enormous machine that assembled planes, filled them with fuel and tons of bombs, and then daily launched them eastward from the UK. Long after this machine could materially affect the course of the war it was still operating at full tilt, with the allies seemingly unable to switch it off. In small (pop < 50K ppl today) cities of Germany you can find plaques in the Marktplätze indicating that the city had been flattened, bombed for the first time, in late April 1945. The machine had been flattening cities in order of importance, and had run down the list to the point where they'd run out of anything worth bombing.
It's hard to argue that any of those bombings were individually "unethical" (assuming you can accept carpet bombing cities at all) because they were bureaucratic decisions with no real room for individual judgement any more. That is a critical lesson both for wartime and for peacetime. We don't really mind if a company makes a worthless product -- it merely goes out of business. But at the state/strategic level it can be tragic.