It’s because of the bureaucracy required to administrate all the different insurance plans.
Our healthcare industry is intentionally inefficient. Services are made scarce in order to maximize the profits for investors. That’s why it cost so much.
Also, the health insurance industry is a middleman who profits investors by depriving patients of health care. Government control of the the healthcare industry would streamline the entire process and remove the profit motive that deprives patients of care.
It’s a profitable investment because health is priceless if you’re sick. People will pay whatever is necessary to be well. That’s one reason healthcare should be a nonprofit industry administered by the public for the public.
Tax dollars should be prioritized to provide what the public needs, and Not loaned to individuals in order to make massive profits for private interests, like we do.
When the "system" loans money to private investors, that’s socialism for the rich. When it loans money for public profit, that's just good policy.