Because all people are equal but some are more equal than others. Especially those with strong party ties.
With the right connections, a person keeps rising in the party system. The richest families that form the topmost echelons of the state and national economies tend to own all the corporations. These corporations are in turn backed by the Chinese state too. It should come as no surprise that with this hierarchical structure, strict work rules and zero chances of unionization/ protest; China has the cheapest, most easily available and the most efficient labor force compared to anywhere else in the world.
The master stroke of opening its cheap labor and land to the global corporations brought all kind of industries to China. They learned, reverse-engineered, stole and hacked their way to a position where the Chinese are now leading in most technology. I guess everyone has heard of how Huawei became the leading telecommunication company in the world by hacking Nortel. They have also been very far-sighted in establishing diplomatic and economic links in Africa in other poor countries around the world. All of this means that they need English+Mandarin speaking Chinese Elite to act as emissaries and representatives of their corporations. Those are the billionaires that they keep minting.