One of the questions I have for people who advocate for a single payer system is, how will it be different from Social Security? With Social Security, government steals from the pot with impunity. In addition, Social Security is not guaranteed to anyone. If there is no money in the pot then there is no money. Government has zero obligation to you. Likewise, as we see with veterans in the VA, if you are too sick and expensive, government has no obligation to you. In fact, government run Medicare turns more people down health care related issues that private insurance currently.
This is a major problem.
People paying in and then having no security based on what elected govts, which change every 2 years, decide to do with the money.
What is the point of a government? Many people don't seem to see it as the organization that should simply make life better for citizens.
Housing, for example, should be a home, not an investment. However govts all over seem to use the housing market as a tool for making money, especially for rich people with spare cash, who can buy and sell when it suits them.
A retirement fund should be just that. People putting in money and the money being assured to them when they come out of it. Private companies are too volatile for something so long term, you put money in, the company goes broke and takes your money with them. Only a govt can really have the security, but govts don't bother with that. Elections are short term-ism, every 2 or 4 or 6 years they're trying to wow you with something or other, and show you what they did in the last term in order to prove it.