From what I have studied their economy was becoming more and more unstable as the war began. Their enormous military buildup was financed to a large extent through deficit spending, including Mefo bills. Between 1933 and 1939 the total revenue of the German government amounted to 62 billion Reichsmarks, whereas government expenditure (up to 60% of which consisted of rearmament costs) exceeded 101 billion, thus causing a huge deficit and rising national debt (reaching 38 billion marks in 1939). Hitler and his economic team expected that the upcoming territorial expansion would provide the means of repaying the soaring national debt, by using the wealth and manpower of conquered nations.
The German wartime economy was very inefficient. Nazi Germany was confident that the war would end quickly; however, that didn't happen. For this reason, a full wartime economy wasn't mobilised until it was too late. Hitler was against the idea of women in the workforce, despite there being a deficit in the male workforce. The necessity for a stronger workforce was becoming clearer and clearer as defeats on the front were building up on both sides. Additionally, there were a number of different conflicting plans within the German wartime economy such as the creation of ministries out of nowhere and these ministries had different conflicts with each other. Consequently, this led to a very inefficient government and economy in a time when they needed a very efficient economy. Albert Speer did try to change things after becoming the Minister of Armaments and War Production and his policies did yield positive results but it was too late.
True, But same applies to US if it was bombed to stone ages by half a dozen world powers. US got away because it was on the other side of the world or it would have done a lot worse than the Nazis. Putting in the context US has not done anything today that Nazis could not 70 years ago.