Keep in mind training pilots can also be cost and resource intensive.
No, the issue is not if you have to destroy a country complete for strategic bombing to be meaningful, but how much disruption can you cause the enemy. Your claim that factories can be dispersed and thus there is no affect neglects the real world problem of Germans being unable to complete fighters because of transportation problems from dispersed factories.
While displaced workers still are working, unless they are displaced too far, which occurred frequently in Japan, this also introduced inefficiencies through increased absenteeism.
Over Japan, the USAAF routinely mined harbors and key straits. Sure, the Japanese would clear the mines but it would block the passage for another day. All of this contributed to the total war effort by reducing the ability to wage war and created inefficiencies.
As I posted, the acute shortage of aviation fuel meant that new pilots were being sent to duty with 50 hours of flight time, an insanely short period. Fuel shortages also affected tanks crew training.
The affect was seen even greater in Japan where strategic bombing, in combination with the blockage and the battlefield losses, and broken the will of the Japan civilians. Sure, there was no way for them to openly rebel, but their potential rage toward the Chrysanthemum Throne was a major contribution to Hirohito deciding to force the issue of surrendering on the unwilling Imperial Japanese Army, throwing them under the bus to save himself.
Thank you all. Very helpful.
davidmich