Axios rightly points a major flaw in healthcare in the United States, that insurance is tied to employment. Another major flaw is even calling it insurance.
Insurance is really about probabilities and statistics, and insurance companies are essentially gambling on the premise that there is a lower probability of paying out money than taking in money.
Car insurance is real, one might go a life time without ever having to file a claim yet must pay for it regardless if you own a car. (BTW, in most states one MUST buy at least liability insurance.)
If car insurance were like health insurance one would be filing a claim every time they took their car in for an oil change or some other repair.
With the frequency of payouts, the real question is, why would any private corporation want to even be in the health insurance business? The only way it can be profitable to a corporation is to take in more money by charging more than they pay out. Can you not seen the fundamental problem here?