What you are paying is a premium for either a Medicare Advantage plan or a medigap policy, which cover services that "regular" Medicare does not cover.
Those supplemental policies are actuarily sound, because the insurance companies that offer them are required to keep them so.
If the core Medicare program were "just like health insurance" it would be required to be stable on an actuarial basis. The premiums would have to rise, or the benefits be cut, to bring the future liabilities into line with anticipated revenues.
They aren't, and it isn't.
I believe the unfunded liability of Medicare is in the trillions of dollars. No matter who is in charge or how it’s run, there will have to be drastic cuts in the future.
Social Security will be similar.
Bernie Madoff went to jail, Democrats go to Wash DC.