Well the entire public policy point of insurance is to have the people who pay in but don't really use it subsidize the people who end up needing it. This dynam

Well the entire public policy point of insurance is to have the people who pay in but don't really use it subsidize the people who end up needing it. This dynamic is why the ACA had an individual mandate, which addressed the incentive of young healthy people to not want to pay in. It would be sensible if we were talking about one society-wide pool (ie single payer), since those younger people would end up being subsidized as they developed health conditions. But as it stands having many pools run by independent companies is fraught with perverse incentives, since an "insurance" company is quite happy to have you as a customer when you're paying in, but much less happy when they're paying out.