I think all of us who have truck campers face this issue. We buy a big super duty pickup, often with a quad cab and a diesel engine. It seems we have a truck that should carry anything you could fit in the bed. Wrong. We quickly find that the truck is heavy but has very limited cargo capacity.
I bought my camper first and then went to buy a truck. The camper sticker had a wet weight of about 2400#. I figured I would need to add another 1000# for passengers and gear putting me about 3500#. Turns out that was off by almost another 1000#. It seems the manufacturer did not include extra weight for the solar panels, gel foam mattress and a bunch of other accessories that were on the camper.
Anyway, my TC dealer and the truck dealers were sure I would not need a DRW truck. It was May of 2010 when I tried to buy my truck. I wanted a 350/3500 rated truck but could not find one. I could not order one because it was too late in the year and I would need to wait until the end of the Summer for a 2011 model. Finally I found and bought a Ram 2500 SRW with CTD and a quad cab. The truck weighed about 8000# and the GVWR was 9900#. Clearly that came up short. If I had been able to get a 3500 SWR, the capacity would have been 12000#. The only difference was the wheels/tires and one extra spring in the rear suspension. So I upgraded the suspension first with airbags and later with Supersprings. Eventually I also had to add 19.5 wheels and tires to take me from overweight for the tires to extra capacity.
Now I have the same TC and a 2018 Ram with CTD and megacab. The GVWR is close but still insufficient. I am a few hundred pounds over the rated capacity. I took my first trip without modifications and then added Timbrens to help with the rear end sag.
Maybe I am cheating the State on registration fees, but I don't think so. Since the TC is removeable I could not register as an RV. That would have saved me a bunch. Because the truck is a 3500 I had to go to "commercial" plates which cost a bunch and have restrictions.