About a year ago I was next to a car at traffic light and noticed a sign on the car. It stated something to the effect that rear seats removed for package delivery. As if removing the rear seats was illegal or something.
Many vehicles spent most of their entire life with only one person in the driver's seat, which is the first one to wear out. I have had a few vehicles like that, as do many people driving giant crew cab pickups, etc.
My '94 Ranger is a factory two-seater. It has optional "sport bucket seats," which were designed more for Explorers than the handful of Ranger regular cabs with the option. They get squished on the back window. Still love them since I'm pretty short.
My '01 reg cab had a 3" longer cab and the school bus bench seat. That truck could legally seat three and physically fit four, at least in high school.