Not to defend China - its amoral indefensible blight on the planet - but the average Chinese citizen being one 1/3 as productive is not the only way the math works out. It certainly can be the case that we are not measuring productivity accurately and/or are using the wrong metrics as a proxy.
For on thing productivity is a measure of progress toward a goal, does China have the same goals we do? I am not sure "Biggest GDP" is really what Xi is after.
I think looking at Europe is good example. They are mostly capitalist but the best parts of it also using the petrol chemical cheat code. Germany is struggling, they have trouble even trying to allocate and spend their own stimulus packages. The rest of the EU make the US debt spiral situation look solvable ;-) by comparison and the bond market does not share that view.
I think you could say that hard-nosed brand of capitalism is what has carried us this far and why we don't look like France right now. I mean seriously compare the BLM unrest, or Jan 6 (if you like) in the US to what is happening in France right now. There is no comparison, in terms of how destructive and destabilizing it is/was. Take away all the various politicking and window dressing about what is going in France right now and it boils down to - a large segment public accustomed to increasing socialism is upset the government won't give them nicer stuff, and government that is by no-means opposed to affording people lots for entitlements pushing back on doing so because those in office recognize it isnt sustainability affordable.
The problem isn't capitalism and it isn't how 'hard-nosed' that capitalism might be it is an ownership and direction problem. Capitalism as described by someone like Adam Smith assumes self interest but it assumed the owner of the capital would be in control of it. That is if you are the owner of a company you want it to continue to grow for at-least-your-life-time but probably that of your children and grand children. Today the CEO is employee and the owners are largely inactive shareholders (they don't vote on much, read board meeting records etc) they are not interested in how the company will perform 20 years from now they are ONLY interested at most in how it will perform between now and maybe the next dividend date. The CEO is only interested in the current quarter and perhaps next, he does not plan to be there longer than 18mons in anycase and is perfectly happy to move on if the quarterly bonus are not fat.
Ross Perot tried to explain this to the public when he said 'Giant Sucking Sound'. Anyone with a brain could see 'trade modernization' was going to create massive windfalls for ownership short term as the divested expensive American workers, real-estate, and regulatory environments and bought cheap labor in Mexico and further afield; but anyone with a brain could see what that was going to mean 30 years on.. Well here we are. An America that can't make things, and I don't think has bright economic future at all, unless we make some PAINFUL choices today to course correct. Because guess what AI datacenters dont care where they are at and models/IP will always be stolen by whoever wants it enough. In the end you have to make things - physical things - people want.