Bottom line, HD SUVs would sell like hot-cakes for a while at least until the market is saturated with them, the economy goes in the tank (along with all new vehicle sales) or we're all gassing up with a SO cord plugged into a transformer.
And all BS aside about vans, yes they are the most economical way to haul a large family and do have the capability to pull a modest trailer while hauling said large family. What they do acceptably or excel at in those categories, they still give up what most people "want" or think they "need" in a vehicle.
-Luxury? Not there. (Idk, maybe you could special order power leather seats and a good sound system, etc, but 99% of the vans for sale are basic transportation rigs)
- All weather capability? Nope, not for the "average" 21st century soccer mom or dad. Sure I just drove a rwd BMW 600mi through a blizzard and didn't think twice about it, but most people even in AWD and 4x4s were poking along like they were in a..... blizzard. It's 2021, not 1981.
- Power? best one can do is the new 6.6 gasser with a 6 speed. Not great even by HD gasser standards.
- Visibility, ergonomics, safety features? Alot of people are now very used to the ergos and technology that comes with vehicles built in the last 10 years or less. Full size vans are a throwback to the turn of the century, minus some mandatory safety updates.
-And the most subjective yet equally or more important to alot of consumers, the image.