For the Japanese. The war was shortened. But by the time of the bomb they were doomed. They could not replace their losses like the Americans could
The Germans were beaten mostly by the Soviets. They (the Germans) were overwhelmed. And they too could not replace their losses like the Soviets could. Especially humans
Not to my knowledge
Economic heft had a lot to do with it as did the weight of numbers
I love science, BTW. But it is not the source of all knowledge.