China already has slaves of it's own, people who have a rural hukou. It creates a permanent legal underclass of exploitable labor with basically zero rights.

What I'm talking about is pretty simple, in China you're registered in the province of your birth, or parent's birth. This registration is called a hukou, and is pretty much impossible to change except in cases of extreme wealth.

Your hukou determines what social services you have access to. Social services in China are paid for at the local level, and are only available to people who have a local hukou.

The problem is that there are no jobs in the poor provinces, and if someone moves to the city for work, they have zero access to the social services that their taxes are supporting, unless they pay out of pocket.

These migrant workers have no labor protections, no unemployment, no local schools for their kids, except for criminally underfunded migrant schools, that are not free.

So you have about 15% of the population of China who you hear about, living upper middle class lives with free social services, supported by the exploitation of everyone else.