Thank you for providing the sources used for your article. While I haven’t had a chance to go through all of them in detail, I can’t help but notice virtually all of them have to do with US health programs like Medicare, Medicaid, and the VA. Given these programs exist in the context of a hodgepodge of private insurance plans in a country with millions of uninsured/underinsured individuals, it’s hard to see how any issues with them relate to the merits of a single-payer system where the system is far more streamlined.
That said, your article stated that a single-payer system such as the one that Senator Sanders has proposed would cost the US $18 trillion. Though you didn’t say so in the article, this would apparently be over 10 years. Regardless, the NPR story you provide as a source for this claim doesn’t actually claim that Sanders single-payer proposal would add $18 trillion to the deficit over a decade. It states that all of his proposals together would, including his tuition free higher education proposal. As the article makes clear, the Sanders campaign strongly contested these figures at the time.
I of course can’t help but notice that you, like other critics of single-payer, do not challenge the fact that overall average outcomes in countries with universal coverage is superior to that experienced in the US. That an American state should have the highest maternal mortality rate in the developed world by far is hardly an advertisement for private for-profit health care, especially given the cost Americans must pay for such terrible coverage.