This is a genuine question. There's probably an explanation for this I haven't thought of, but it just occurred to me and I thought I'd post it here. I'm sure a central reason would be that Japan was going to surrender, while Germany wasn't at the time.
You don't. Strategic bombing like what happened at Dresden and elsewhere has always had a minimal impact on a country's ability to manufacture war materiel while killing hosts of innocent civilians. We figured this out partway through WW2 and instead of backing off to save innocent lives and save our bombs for the battlefield we decided to double down and invest extremely heavily in the tactic anyway, blowing up marginally more useful targets and killing scores more in the process.