I would not get too carried away being happy about getting rid of it, if we did not have medicare but had insurance instead I think we would just let the old people die. That is the way it used to be you know. The health-insurance industry is designed to make a profit, not provide medical care. You simply cannot make money by insuring high-risk pools such as old people without charging very high premiums. Economically you can not beat economy of scale, no way an insurance company can get the same price for a knee used in a knee replacement buying 80,000 that a single payer could buying 600,000 a year.
If you look around the world at the way others do it you will find that some form of single payer system is the most economical and the most beneficial to the most people. We insure about 55 million Americans this way already so don't act like it is some socialist invention.