I ask because in my country they have slavery. It is de jure slavery, but the level of paperwork they have to do in order to wrangle somebody into a prolonged slavery sentence is quite low. They make clothing and routine goods for each state under the auspice of "punishment" and "rehabilitation" but its really just slavery. Like my very own brother is incarcerated, but he wasn't sentenced to slavery, but the slavery is somehow in an unwritten manner just implicit in the incarceration, my brother earns $4 per week working for the prison. All of the domestically made appliances use this sort of labor, most domestically made office furniture, office supplies, sorting e-waste, producing textiles, road maintenance, park cleanup, graffiti removal, harvesting crops, some even farm fish, make lingerie for the ladies, or run craft shops on etsy.
It isn't just a 'practice', its the law, lookup the cases Ruffin v. Commonwealth, Butler v. Perry, Imprisoned Citizens Union v. Shapp. So how are european countries keeping the cost of goods low without that slavery mechanism?