In some states the trucks can be registered as a car if they have a camper, so no weight fees. When my camper is off I put my shell back on. The weight sticker inside the door post is for commercial use as a hauler with a commercial license on the outside of the truck. Like a car your passengers may overload the vehicle based on the sticker inside the door. I don’t know of very many people who weigh their passengers and their car.
That doesn’t mean that you shouldn’t weigh your loaded pickup and install tires, wheels and suspension that can carry the weight safely, including air pressure, which is most critical. Then you must drive accordingly for your vehicle and load which you would have to do even if all your numbers coincided with the door sticker. While the door sticker has a lot of nice info it doesn’t mention rollover height limitations, this like all other factors on upon the driver.