Insurance relies on having a diverse enough pool to distribute the risk, but health insurance can only do that in one of two ways. Either try to force participation, which either doesn't work (as we've seen...not enough healthy people paying in) or incentivizes more use of benefits (after all, you're paying for it anyway) and increases the pool's risk/cost, or voluntary participation and more competition, in both range of coverage and being able to cobble together pools that offset risk. Participation need only be forced because it is a Ponzi scheme, since it is not sustainable without a stead influx of healthy payers.paying for other people is literally the entire point of insurance. Its literally the in the fundamentals of how it works by distributing risk. its not a ponzi scheme your just ignorant.
Insurance is not inherently charitable (paying for others). No one knows when they may need the full benefits they pay for, and the insurance companies trade that peace of mind to hedge against higher utilized policies. But even on the free market, if an insurer cannot entice enough buyers, they cannot sufficiently defray their liabilities.