You either don't live in the US/Canada or you don't ride in areas where people drive full-size and "heavy duty" pickup trucks. The Ford F250 for example has a roof that's 7 feet high.
https://www.reddit.com/r/Trucks/comments/10vb432/f250s_just_...
The roof on the old F150 is barely above the door sill on the new truck.
...and then people go and put bigger rims and lift kits on them.