Working for money isn’t slavery. Slaves don’t get to tell their bosses to go to hell and go get another job. They don’t go home for Chinese New Year and never come back because they’ve finally saved enough money for a house or paid their sister’s way through university or heard that the money’s better in another city or factory.

Slaves are property. For all the many, many awful things that are wrong in China there is no slavery.

Minimum wage laws are not economically binding in less developed countries except sometimes for the professional managerial class. They sure as hell aren’t binding in Communist countries like China or Vietnam. You need a strong and powerful state to enforce minimum wage laws. If you can’t manage to vaccinate all the children in your country the laws may be on the books but they won’t be followed.