Not the point. The rest of the world (specifically EU and China) has played catch-up and if the US wants to maintain its Tech dominance, you still need H-1Bs to maintain your momentum.
In China's case, the population decrease is actually a positive for them since they are primarily an exports-driven economy. A lower population means investing into automation at an extensive degree to retain the same production levels, without the need to feed that much of a population. And if China really needs an extra labour pool, they have no qualms doing the Middle Eastern playbook and bringing in tons of workers from low-wage countries to do the dirty jobs - in fact, they already do that with Africans.
Russia is in trouble though, but given that their industries are slowly being eaten by Chinese conglomerates, they are a has-been now.
Without the large population not to perform "dirty jobs" but to participate in Chinese society to generate domestic demand, it is unlikely that China will continue to require ongoing stimulus just to keep the economic model functioning. See this (https://www.omfif.org/2025/03/china-has-just-raised-its-debt...) regarding the increase in debt held by China and its localities.
This need for "permastimulus" just to keep the economic model working is the problem: China needs to be rebalancing its economy away from production and into consumption. Unfortunately, a declining population also has declining consumption.