Not even they could do that. I've lived in a country with universal government-funded healthcare; many things are better than the US system (low bar, I know), but wait times are very long and standards of care aren't magically any less sucky.
There are definitely examples of universal healthcare that seems to operate well in small universes.
From CMS on National Health Expenditure [1]:
> NHE grew 2.7% to $4.3 trillion in 2021, or $12,914 per person, and accounted for 18.3% of Gross Domestic Product (GDP).
> On average over 2021-30, National Health Expenditures (NHE) and Gross Domestic Product (GDP) are both projected to grow 5.1 percent per year; as a result, the projected NHE share of GDP in 2030 (19.6 percent) is similar to 2020 (19.7 percent).
McKinsey [2] cites
> Of the nearly $4 trillion spent on healthcare annually in the United States, administrative spending is about one-quarter of the total; delivery of care is about three-quarters.
Nearly a trillion dollars in administrative spending that could otherwise go into care delivery! (Yes, some administrative spending will remain, but the pie is so large).
That just shows that entrenched forces are strong.
[1]: https://www.cms.gov/research-statistics-data-and-systems/sta...
[2]: https://www.mckinsey.com/industries/healthcare/our-insights/...