Is there some reason we can't refuse to import their goods or offset their lower cost of goods due to slavery by imposing tariffs?
Seriously, I can do this all day.
Seriously, I can do this all day.
To address your question as why this is allowed to continue, you'd have to ask those within the US and countries that allow it to happen.
Australia addressed this in 1907 or so with the Harvester decision and other related law cases that became foundation to working conditions.
https://www.fwc.gov.au/about-us/history/waltzing-matilda-and...