You suggest that people should have their wages garnished to pay several hundred thousand dollars? That’s essentially a mortgage for 30 years. Even small medical expenses will run into the tens of thousands. Making all drivers have insurance as a part of licensing a car keeps rates lower than they might be if insurance was optional. The cost to insure all the state’s drivers is the same. The question is how large the pool of drivers is that pays for it. If everyone pays for it, the cost per person is lower.