Yeah, SUVs used to ALL be on truck chassis, so far as I can recollect. People with trucks put caps on the back and the automakers saw a market, not THIS market.
Then minivans became unfashionable, so they took FWD car chassis and put SUV-looking bodies on them and viola, a HUGE market. Then "mini-utes" appeared, also station wagons raised a bit and given AWD sometimes. I had minivans for 20 years and they are very capable for their purpose. They don't tow, but they have a lot of volume inside and get OK mpgs. They don't "look" cool apparently. I didn't care. My first was a Dodge Caravan with a very anemic 4 cylinder engine and 5 speed manual transmission. I had to plan ahead to merge onto freeways. I think we still had a 55 mph speed limit at that time.
The interesting part about this is if you go back a bit further to the invention of the minivan.
Vans, like the original SUVs, were built on truck chassis. They were big, bulky, rode high, with truck engines and RWD. The "mini" van just took a basic van body and put it on a FWD car chassis. It made the ride smoother, the COG lower, the handling better, etc. For all the people who didn't want station wagons, the "minivan" became the new thing.
SUVs were around, of course, but not all that popular yet. When people decided minivans were uncool, everyone started jumping into SUVs. They had all the same problems as full-size vans though. High COG. Rides like a truck. Terrible gas mileage. So the "crossover" was invented--an SUV-like body on a FWD car chassis. In all honesty it got rid of most of the "utility" of the SUV, but it kept the "cool" styling.
And now I've got a Ford Flex. Which is basically a big station wagon, but my wife always chides me when I call it a station wagon, because station wagons are uncool.
So we've come full circle.