You're dreaming. Commercial payer organizations have low profit margins, especially since the Affordable Care Act (Obamacare) instituted an 85% minimum medical loss ratio. Some of them already operate as non-profits. Eliminating them wouldn't free up nearly enough funding to make "Medicare for All" work with a mere 4% income tax increase. Do the math.
You appear to be confusing margins with absolute amounts. Eliminating all health insurance profits wouldn't be sufficient to close the gap on your "Medicare for All" proposal, not even close. I'm not necessarily opposed to a single payer system, but you need to do the math and be realistic about costs.
