I dont care about how many green cards the states has issued, its a backwards looking metric.
Comparing visa datasheets and application requirements will not give you the complete picture on immigration. I cant iterate case by case over every western nation here so I will limit my myself to the US since this is HN.
For most H1B immigrants residing in the US on dual intent visas, there is no realistic pathway to PR either, due to country caps and observation that one country supplies a majority of immigrants to the US.
Most H1Bs here spend their full careers in an anxious immigration limbo between USCIS, unreliable employers, power tripping border agents with 3/6 year renewals and periods of restriction on travel. Many who arrived to the US pre-2001 are still yet to recieve their promised green card. That is not practical in any meaning of the word. Immigration and PR into other western nation is an order of magnitude easier.
Many without the fortitude pack up early and return home, the USCIS does not account for them AFAIK.
Most immigrants get the same or better experience under the Z visa with minimal pretense and bullshit. The Chinese govt is kind enough to dictate reasonable terms. You renew every 3/5 years at the local visa office until you reach 60 and head back home. You arent treated like a criminal at airport immigration. The points system used for Z visa not a hurdle for anyone remotely compenent. It does not ask you to learn fluent Chinese, getting paid sufficently, having enough prior experience making grants enough points, its table stakes for most immigrants. If you want to reside in China beyond 60 you can figure out an avenue with immigration consultants, but it rightfully requires justification.
Peering into the future, net legal immigration into the US has passed its inflection point. As DJT admin looks into curtailing OPT, H1B and birthright citizenship I would say US is looking worse today than China in matters of immigration. Compared to just 2 years ago, 2024, nobody coming to US is expecting to stay permanently. That door has long shut. In contrast foreign student enrolement in Chinese universities is trending higher every year. Eventually this may lead to better terms to reside in the country.