Socialism

The USSR had low wealth inequality by design, and was more publicly owned and centrally planned. This led to numerous benefits, but also drawbacks such as brain drain.

The PRC took the opposite approach. They allow billionaires to remain in the PRC, investing and developing Capital there and not elsewhere. They maintain a balancing act between capitilation and domination so there isn't the same Capital flight and brain drain, because you can still go to China to get extraordinarily rich.

The Chinese path presents a difficult contradiction towards their Socialist goals, but their method of "boiling the frog" has set it on course to continue surpassing the US while remaining entangled in the global economy, rather than isolated like the USSR was.