If I wanted lots of floor space and also a dry bath, larger fridge, and large holding tanks, that one gets with a trailer I would get a conventional travel trailer and not a 5th-wheel.
With a TT all the floor space is on one level, unlike a camper or a 5th-wheel. With a TT my truck's bed is available and I can put on a fiberglass cap and add roof racks and take along a lot more stuff, like bicycles, camp furniture, kayaks or canoes, small boat, etc.
On my last trip through Utah and Nevada I saw a very high percentage of travel trailers being towed by pickup trucks and in the beds I saw more often than not a small ATV and sometimes two ATV's in the bed. Much easier to do this with portable ramps than to try to manage this with a 5th-wheel trailer.
Both types of trailers make it easy to reach a destination spot and unhook the truck and use it to travel around. I would prefer doing so with my toys in the truck and not having to leave them at home.