You could examine any single developed countries economy for similar examples but I'll use the U.S. because I'm more well versed. Obviously slavery and child labour were essential to the U.S. economy from 1776 to the early 1900's. But neither has actually disappeared. The economy of the U.S. extends outside of it's boarders via it's corporations and colonies. American chocolate companies rely on cheap chocolate production which is kept cheap because the land owning and managerial class in places like Ghana relies heavily on slavery and child labour. The U.S. put pressure on Haiti to keep wages at pennies in hour because U.S. corporations rely on Haiti for production of things like textiles and clothes. The U.S. has hundreds of thousands of people doing forced labour in prisons and jails aka slavery. You get the picture. A group of people in one place can struggle for liberation but capitalism demands that it be a global affair to guarantee profits can always sore through the most extreme exploitation they can get away with. You can paint a similar picture for Japan, Germany, France, etc. any place that found itself one day with labour laws or unions would either use it's imperial rich or it's allies imperial rich to find a place to exploit like they used to exploit their neighbors a few towns over.