For example: https://www.kff.org/health-policy-101-international-comparis...
But a basic google search returns hundreds of sources
And the US is near the top of the GDP rankings.
https://www.kff.org/health-policy-101-international-comparis...
The metrics the US does poorly on seem like they're more of an access problem (than acute care being bad), which suggests broadening access to affordable healthcare would be the best redress -- i.e. universal healthcare.
The US health system seems like it would be better served by explicitly breaking it into a multi-tier one.
Basic tier: universal health care for basic access and procedurings, including proactive health measures
Everything else: private health insurance available (not attached to an employer)
It really does matter. I'm no fan of our current system either, but by and large people do receive quality healthcare on it. If you rip out that system, you need to replace it with something that's at least meets the same standard.