I have two vehicles, my girlfriend has another one, and despite living in one of the higher insurance premium areas in one of the highest insurance premium states in the country (Oakland County, Michigan), our total bill with full coverage and relatively low deductibles is around $7k/yr. A family with 4 cars total (two driving age kids, two parents with cars to drive to different jobs) should not be massively more expensive, likely only $3~4k more than my bill, making it about half of the headline number. To do worse than that, you'd have to live in the worst part of inner city Detroit with the highest insurance rates and have full coverage or massively more expensive vehicles... I don't think the math checks out, really.

I do know people who have very very high bills, but they have one of 1) very high end cars (911 GT3 RS, Bentley, etc.) 2) something rare insured at full value of its rare nature or 3) actively stating to the insurer that it's a track car being raced on the weekends. All of those happen around me, but those aren't the modal case.