Ultimately the Germans had far overreached the capacity of their smaller nation to play in the really big leagues against the US and the ussr. Technological excellence could only get them so far. Even when everyone had been weakened by the Depression.
US armed forces in WWII became legendary. Solzhenitsyn in a different context later bemoaned "the accursed capacity of our (Russian) people for suffering."
Many Russians and Ukrainians originally welcomed the Germans as “Liberators”.
Hitler made a mistake in not treating Russia more like France or Holland. Red Army soldiers would have surrendered in droves knowing that the Germans would treat them decently, it was better than continuing to live under the Stalinist boot.
Now of course, Hitler would have none of it, because he saw the war as a war of elimination. But, Hitler once he won in Russia then could have turned around and did whatever he wanted to the Russians, with the threat eliminated.
Well, our own Declaration of Independence did observe that “mankind are more disposed to suffer while evils are sufferable”, but although there was no availability of ballistic arms to the general populace of Russia, Solzhenitsyn did observe that Stalin’s “cursed machine would have ground to a halt” if the people had stood up for themselves using whatever was at hand. The left in Russia perfected division and conquest via the doctrine of “abolition of the family”.