Insurance in general is a subscription for a range of protections against certain events if they happen. That itself isn't the problem. It's the many companies setting different subscription prices and rules, and then having or finding loopholes in the rules to say "oops, sorry, can't help you there". For health It's also where some of them have deals with companies to give benefits for the company to use as a retention tool for employees.

Now we (talking US) could take the parts of both for health insurance and widen the pool of people to everyone, while also having regulation over a single type of insurance that would be able to cover the worse situations because it can spread the cost over the larger pool. This would also have a subscription, but one that would be lower for everyone and even waived for those at the lowest income.

However such a single payer insurance threatens the industry of health insurance as well as pharma, and guess who has lots of lobbyists in Congress to protect their interest.