That's both not true (the PRC exists, and alone is sufficient to disprove that no country with universal coverage exceeds the US on any of the measures you listed) and not relevant, as none of those are significant per-capita or per-GDP healthcare cost drivers.
The PRC has universal healthcare coverage entitlement by national policy, financed and administered largely by local governments under national standards (with central subsidies to poorer regions), and has over 95% of the population covered through public-funded programs. [0]
> 2. that it's something that is to be imitated?
The claim was no country with certain features exists; being worthy of imitation was not one of the features.
I never advocated emulating the PRC either in general or in the specifics of their mechanism of addressing universal healthcare access; in fact, I specifically pointed out that, as well.as being false, the claim about countries sharing those features was irrelevant to the healthcare discussion (which implies that a country meeting the supposedly unmet description has no particular reason to have special status as a model for the US.)
[0] https://international.commonwealthfund.org/countries/china/
That's saying nothing of its outcomes or service level by the way. Simply in reference to its structure.
It's not even in the same ballpark.
This argument is so bizarre. Larger population sounds like better economies of scale to me. And social diversity? I mean we're talking about Homo Sapiens here. A kidney is a kidney is a kidney, no matter your cultural background.
Healthcare also hasn't shown that it can scale or that margins increase with more centralized services, while maintaining service levels. Said another way: doctors (the bottleneck for service) are expensive to grow, take a long time to make, in high demand, and work serially (no parallel service provided).
It's a structural problem, not just a policy one.
Why is this relevant?
The UK for example has a population of 60+ million (v US's 300+ million), if that figure doubled or halved, I don't think that would fundamentally change how the NHS operates. Just like it doesn't fundamentally change how it operates in central London or the Scottish highlands.
No country on earth with single payer or other universal coverage has anywhere near the number of citizens nor geographic or social diversity as the US.
Now, that doesn't mean we can't learn from those countries, but our own smaller scale federal health care systems (medicare, VA, tricare) are already large enough to compare with and done so.
It's quite unfortunate, but the entire federal system has to change in order to lay the groundwork for a single payer system.