GVWR is a totally made up number, and it only serves a regulatory need, depending on whatever market niche the manufacturer wants to fill, and what paperwork has been filed with regulatory agencies, nothing more.
Case in point, my 2016 F250.
Front axle WR: 5200 lbs
Rear axle WR: 6100 lbs
Tire ratings: 3450 per tire (2 tires per axle adding up to 7900)
GVWR is 10,000 lbs. What combination of the above numbers adds up to 10,000 lbs ? (Hint: using regular math, no imaginary numbers, or multiple dimensions)...
I can't register it for 10,000 lbs in my state, I can only do either 8000 lbs, or 12000 lbs, no other options. I asked the lady at the DMV what would happen if I registered it for 8k, but I was found overweight. She said I'd get a ticket.
Guess which one I registered it for? :)