Strategic bombing achieved the destruction of german factories.... both the RAF and USAAF.Well we could have used the American approach of mass slaughter and deportation to isolated wastelands that no one wants. Or if a group from a neighbouring nation seeks to gain control of some of our territory because a minority in that territory identifies with their nation would the US happy say "Oh yes you can have it."
On the 2nd point if nation A has about 3 times the population of nation B, plus vastly greater resources, isn't subject to blockade, bombardment, blackout and threat of invasion, enters the war over two years later than B and gains considerable information from B's wartime experience there would be something seriously wrong with A if it can't at least match and in some ways surpass B.
Frankly both nation's leaderships fouled things up with air power during the war was strategic bombing was in most cases a waste of time. It was effective against Japan because by the time the B-29 were used on lower level bombing attacks there was no real defensive operations and the Japanese housing and urban system made for massive civilian casualties. However for most of the war BC was a huge waste of sparse British resources and similarly the primary role of the USAAF in strategic bombing in Europe was that, once they abandon their doctrine that the bombers could fight their way through on their own and got long ranged escorts, the B-17s and B-24 made idea bait to lure the LW fighters into the air so they could be shot down.
The US supplied countless resources to Britain during the war to make sure they did not run out, even with a lot of the aircraft Britain had being home made.
Even before the range on the fighters like the lightning and the Mustang were increased the bombers were damn good at thier mission, even with the amount of losses they took.
Once the lightning and the Mustang had the range, the bombing missions became safer and the kills by the fighters did increase. Of course lilots still died.
One has to look at the design choices of the two forces to see where they focused thier strengths in