Looking at a crash between two vehicles of very different size isn't a fair test. Smaller cars are much more able to avoid getting into wrecks in the first place. We fully expect, simply based on mass, that vans will be better at passive safety, and worse at active safety.
According to the IIHS, for example, the little 2-door Honda Civic has about the same fatality rate as the safest large SUVs.
People in small cars aren't "taking a big risk". About as many people in America die of influenza as car crashes, so if you're driving an SUV but haven't gotten a free flu shot, I don't believe you're doing it out of some calculated risk assessment.
The fundamental connection: people who drive SUVs and people who skip flu shots don't care about externalities.
It's not that I don't care about externalities, but that I'm going to weigh them against direct concerns. It's true driving an SUV might have a small percentage impact on the environment. It's also true that it slightly increases my chances of killing someone else in an accident. But if it significantly decreases the chance the person killed in said accident is my wife/kid, I'm going to prioritize that over the "dangers" SUVs provide to others.
Also if you have a big enough family there is no way to haul them around on a tiny car unless you shove some kids in the trunk.
Besides. I am no boomer either.
Thanks to ever more stringent rollover requirements modern vehicles can carry some pretty big things on the roof. You just have to ignore the part where people judge you for it (so I understand why people don't do it).
Two adult homes can presumably have a big car and a small car, and prefer to take the most efficient choice for the given trip (and have the shorter commute take the less efficient vehicle), but generally, people need to occasionally move stuff around.
It is, also, safer. I've seen what a minivan does to a Corolla, and I'd much rather be in something the size of a minivan. I sit higher, have better visibility, etc.