I reviewed the number and was planning on a travel trailer for my first RV. We found a 5th wheel that was fine for my 2013 RAM 2500 diesel. Max load we've ever had the trail at was 11,800. But I rarely have two touring motorcycles loaded. And we had another couple with us, so that added about 500 people in gear in the truck. All total I was under GAWR by 300 pounds, and GCWR was under 22K.
I have learned more about RVs since then, and in planning for a future newer camper, I bought a 2020 RAM 3500 that will pull anything we are looking at. Mostly stuff under 20K trailer max.
If you are pulling more than local, traversing mountains, etc, then more truck is better than finding out you do not have enough truck. HD truck frames and brakes are just more suited for pulling heavier loads. Fuel mileage and maintenance differences between a 1500-2500 are negligible. Just be sure to compare gas to gas or diesel to diesel.
I am a diesel aficionado for pulling in the mountains. But I use my motorcycle as primary transportation.