I guess insurers want to avoid being bankrupted by a single disaster, and prefer that the insured person goes bankrupt instead. Unclear what is the socially opt

I guess insurers want to avoid being bankrupted by a single disaster, and prefer that the insured person goes bankrupt instead. Unclear what is the socially optimal policy, but I'd anyway assume if a car accident ever causes like $1B in damages, government will end up paying the bill.