I can fit bigger stuff in my crossover with the 2nd row folded down than most of these emotional support vehicles can fit in their bed. And I can rent a truck once a year when I need to move something big. These things are such stupid shapes.
It could have a pass through rear. Similar to the avalanche. I’ve always wished more trucks had that to increase bed size when I need it and don’t need the seating.
You can't fit a full sheet in a dual cab Hilux, Ranger, or DMAX (etc etc) either but these utes sell in vast quantities. To get a dual cab in something not ridiculously large (and not a cab over design) the tray size will inherently be compromised, it seems however that people still go for the extra seats much more than single cabs with more useful tray sizes.
Unfortunately you're in the minority these days, at least in the eyes of manufacturers. It appears that dual cabs are what sell so they're what get made.
The lack of useful tray sizes in utes is one reason I ended up going for a van for something to put my dirt bike in - unlike most of the utes I was finding within my budget it actually has a load space long enough to fit the bike with room to spare and low enough to roll it in easily.