Having more equipment doesn’t mean having more people or a better developed logistic system to get all of that stuff across two oceans in one piece. For example, during the Battle of Britain, the UK were able to surpass German production of fighters but were running out of people to pilot them.
The Battle of the Atlantic was won by first and foremost intelligence efforts. Being able to route convoys away from where ULTRA was telling us where the subs were was what ultimately turned back the “wolfpacks”.
In the Pacific the US was able to isolate and overwhelm its targets but still had to slog from island to island despite numerical and logistical supremacy from 1943 onward.
The fact that the US was able to wage both its wars simultaneously was an economic miracle in of itself. The fact we still had enough resources left over to work on the Manhattan Project was just astounding for its time.
