Insurance companies want money to come in and never go out. If they could they would sell life insurance to dead people and homeowners insurance to the homeless.
Customers want to pool risks with other customers that are lower risk than they are. Florida homeowner want to be on a national market because they are the highest risk group. Obviously the rest of us want Florida to be separate.
But if there are ten companies offering car insurance and one is known to never pay out, the customers will migrate to the nine who do. Car insurance may be mandated in some states but no one is forced into a particular company.
In the UK, car insurance companies have actually been loss-making recently, despite car insurance being mandatory. It's not a guarantee of profit, especially not given how hyper-competitive the car insurance market is here.
