But families towed tent trailers back in the 80s behind their sedans and station wagons, too.

Maybe there's a bit of circular reasoning going on here where people bought giant vehicles because they liked the aesthetics and internal roominess, and then the prevalence of giant vehicles opened up the market for larger and heavier towables— rigid body RVs, seadoos, a trailer full of gas dirt bikes, whatever it is.

I also feel like in past times, it was much more common to see a two car household with two very different cars, with one being a hatchback or sedan for getting the family around down and doing grocery runs, and the other a truck or van for those occasional "hauling" requirements. Nowadays I feel like many times it's two big SUVs, just tuned to his and her brand tastes rather than two shared vehicles for different usages. I'd be interested to know if the stats on multi-car households would bear this out.