You have to look at the total cost of labor per unit. In the USA it averages 7%. So the cost of any "widget" would still be $.93 even if slave free labor was used. But labor isn't totally free in the third world and then there are added shipping costs. "Slave" labor is still about 3% of the finished unit price. So the unit cost of the imported "widget" is $.97 A net savings of a whopping 4 cents on the dollar on a perhaps lower quality item.
I hope you can grasp that.
And when you are dealing with low profit margins and millions of units, a savings of a few cents can significantly impact either sales or profits.
I hope you can grasp that.