This is the same error in judgement that makes people have an idea that everyone works "9 to 5". That is a good song, but a bad statistic.Why do we need traffic at 2 am when 99% of people are asleep?
Just look at the schedules for warehouses. Or food processing plants. Or hospitals And services like the police and fire and, today, DoorDash and the like. Restaurants often have afternoon and evening shifts, and we know when bars are the busiest. And then we have people who work Tuesday to Saturday or some other non-M-F schedule.
And also keep in mind that a lot of road work is done in overnights, so data about that is very significant.
For radio, there is little local sales for overnights, but we want to be on the air because being "your favorite station" at 2 AM often means that you are that person's choice in salable hours.