https://en.m.wikipedia.org/wiki/Truck_wages

The obvious social costs are that slavery is legalized through debt and slavery anywhere in any society results in social stratification and internecine hostility, violence — mostly across class lines.

This generally also promotes misogyny and economic oppression of women (both by the economically privileged classes, and often as a sort of consolation prize or concession to the male laborers in the lowest classes).