Once you get to a large camper with slides that requires a dually truck you might as well get a class C motorhome.
With a 5th-wheel you are much more limited as to where you can stop. Going through places like Yellowstone or Arches or along the California coast there will be very few places if any where you can pull over for any reason. Much easier to do this with a camper or motorhome.
With a trailer you can park it at a campsite and have your tow vehicle to drive around the area. There are advantages to pulling a conventional travel trailer as opposed to a 5th wheel. With the conventional the bed of the truck is available for storage and cap or shell can be used as well as a roof rack. Anyone wanting to have a small boat, kayaks, canoes, bicycles, ATV' and the like while traveling around the country.
A camper is the least suited for hauling around extra gear though you can tow a boat or trailer with your toys behind the truck.