Why not abolish employer-provided health insurance?
The car insurance works because the incentives are aligned. Some people pay more for higher quality/coverage insurance. Some people pay less for cheaper insurance. The repair shops cannot charge arbitrary prices since the customer does not want their insurance companies to overpay, or else the customer’s premium will go up next year. The insurance companies cannot charge premium way higher than the market or else; the customers would leave. If they charge too low, they go out of the business.