They could have ran a conventional air bombing campaign against tactical targets, but they decided to drop nukes on a “tactical” target in the middle of a huge city!>

I hate to be the bearer of bad news, but they did that AS WELL.

Operation Meetinghouse was the US firebombing of Tokyo on 9th-10th of March 1945 which destroyed a 16 square mile area, killing over 100,000 civilians and making millions homeless

There's also the B-29 raids america launched from the Marianas that lasted from 17 November 1944 until 15 August 1945