Disclaimer: I think the current U.S healthcare system is hilariously bad and should be heavily reformed.

Insurance is not a bad thing, and there is a clear product involved in it. To demonstrate, you can go to a doctor in the U.S and pay in cash for the treatment. As I've understood it, you can even negotiate lower prices than the list prices if you are paying in cash. Still, it's probably going to be expensive to the point of potential financial ruin.

This is the product that insurance offers in any domain it operates - buying your way out of risks you cannot accept. Fundamentally, the concept is sound, albeit very poorly implemented in the case of U.S healthcare.

It's basically just a bunch of people pooling their money together and having that pool of money pay in the case of an adverse event.

One of the primary alternatives to the mess that is U.S healthcare today is in fact another form of insurance - it's just that enrollment would be mandatory and as such the risk spreading would be as uniform as possible, along with subsidies for people carrying higher amounts of risk. That's fundamentally what universal healthcare is in other countries.