Right, but if you’re willing to rent, might as well just rent a truck on demand. At this point you’ve shifted the goal posts to, “why do people buy things and underutilize them instead of renting on demand”?
Why have a guest room when there are hotels you can send visitors to?
Why have a 4 door car that incurs most of its mileage in a commute with 1 or 2 people?