The justifications I've heard have nothing to do with the quality of care, and everything to do with subsidizing the costs hospitals bear for being required to

The justifications I've heard have nothing to do with the quality of care, and everything to do with subsidizing the costs hospitals bear for being required to treat uninsured populations who won't pay your bill. E.g., if someone shows up at a private medical office and can't pay their bill, the office has no legal obligation to treat that person. If someone shows up at a hospital emergency room and can't pay their bill, that hospital is required to provide emergency treatment regardless. It seems like a horribly inefficient and inaccurate way to address this issue. I think broadly, the value-based model (where cardiologists are paid to keep their patients from needing expensive surgeries, instead of paid per expensive surgery) is probably the right model for the future of medical care, but I have doubts about how successful its implementation will be.