You are confusing health "insurance" (which is not insurance as such) versus things like life insurance and property insurance. The US health economy is flawed

You are confusing health "insurance" (which is not insurance as such) versus things like life insurance and property insurance. The US health economy is flawed in many ways that have been discussed endlessly. On the other hand, more usual insurances are actuarial and work on the basis that an insurer shares the risk across the people/property that is insured and charges appropriately. Most insurance of that nature make their profits from investing the income, relying on their actuaries to calculate the expected losses due to claims.