The whole point of the war for the Nazis was to conquer new land in the east (and destroy the bolshewists). They initially did not wanted to have war with UK or France or US. They wanted to fight with them against the inferiors. It was a racist war - the aryans against the slavs - to establish the right place for the aryans as rulers (it was also not so much about "german", it was about race).
Also it was not just the US fighting and winning against them - I believe there was another power to first capture Berlin (that also was good at mass producing).
And technically it was mixed. Some german designs were quite good, reliable and mass producible, others overcomplicated and too heavy. I doubt the war can be reduced to this question, nazi germany had enough weapons and its war industry was working full power, it was just so stupid to get itself into a war on all fronts (and for example declare war on the US in solidarity with Japan, but did not demand Japan to declare war on soviet untion in return).