The conventional bombing of Japan was scheduled for massive increase. To quote Ian Toll's "Twilight of the Gods":
> If the war had lasted any longer than it did, the scale and ferocity of the conventional bombing campaign would have risen to inconceivable new heights. [...] At the height of the bombing campaign, between May and August 1945, a monthly average of 34,402 tons of high explosive and incendiary bombs were dropped on Japan. According to USAAF chief Hap Arnold, the monthly total would have reached 100,000 tons in September 1945, and then risen steadily month by month. By early 1946, if the Japanese were still fighting, eighty USAAF combat groups would be operating against Japan, a total of about 4,000 bombers. In January 1946, they would drop 170,000 tons of bombs on Japan, surpassing in one month the cumulative tonnage actually dropped on the country during the entire Pacific War. By March 1946, the anticipated date of the CORONET landings on the Tokyo plain, the monthly bombing figure would surpass 200,000 tons.
> The conventional bombing of Japan was scheduled for massive increase.
Allegedly.
It's possible it's true, but claims like this have the incentive of selling the "atom bombing Hiroshima and Nagasaki was necessary and justified" narrative behind them, so that should be taken into account as a factor.
It doesn't even have to be consciously disingenous - the more one can convince oneself (and thus eventually others) of how destructive and costly conventional warfare would have been, the more digestible the nuclear option becomes, so there's a lot of motivation to fuel some motivated reasoning.
Professionals talk logistics indeed. To imagine what kind is pipeline would be required to enable such a venture. Producing, assembling, and shipping millions of tons of explosives as a continual operation.
> If the war had lasted any longer than it did, the scale and ferocity of the conventional bombing campaign would have risen to inconceivable new heights. [...] At the height of the bombing campaign, between May and August 1945, a monthly average of 34,402 tons of high explosive and incendiary bombs were dropped on Japan. According to USAAF chief Hap Arnold, the monthly total would have reached 100,000 tons in September 1945, and then risen steadily month by month. By early 1946, if the Japanese were still fighting, eighty USAAF combat groups would be operating against Japan, a total of about 4,000 bombers. In January 1946, they would drop 170,000 tons of bombs on Japan, surpassing in one month the cumulative tonnage actually dropped on the country during the entire Pacific War. By March 1946, the anticipated date of the CORONET landings on the Tokyo plain, the monthly bombing figure would surpass 200,000 tons.