The two aren't independent, though. When you have to pay hundreds of thousands of dollars for humans to operate an airplane, you might as well get the most out

The two aren't independent, though. When you have to pay hundreds of thousands of dollars for humans to operate an airplane, you might as well get the most out of the fixed cost of the airplane to begin with. If you don't have to do that, you can build cheaper smaller airplanes to fly cargo on routes that wouldn't be economical at human operation scale.