Riskier drivers need to pay more because they’re more likely to take money out of the system.

They don’t need to pay more. It just feels more fair that way, on an individual short term basis.

But when thousands or millions of people are all pooled together, the individual difference in risk gets flattened out to be practically negligible.

To your example of the 16yo with a Porche. When you’re young, you get car insurance for cheap. Then as you get older, you pay the same while you’re risk that day/month/year goes down. But after your whole lifetime, in the end it’s all the same.