Like, it doesn't make sense. My insurance policy is about $600/year and covers up to 25 million(!!!) euro in 3rd party damages. Like, I'd need to crash into several Bugatti Chirons or a plane to actually exhaust my policy.
I guess the reason why US allows it is because the society is so litigious - if you have that amount of money to self insure you also have enough money to fight pretty much any claim against you.