What you call "repackaging", everyone else considers manufacturing. True, a Chinese worker might make a medium-value item such as a tire, and a Mexican worker might make another medium-value item such as a seat. However, those items are then manufactured into a high-value manufactured item known as a "BMW" by American workers.
There are cost efficiencies in having lesser-skilled workers put together cheaper items. However, at the end of the day, American workers are the ones manufacturing the big-ticket item at the end of the manufacturing chain.
That is a good thing. Wasting the highly-trained, efficient American worker on textiles and other low-end manifacturing is not smart economic policy.
They shoulda gone into brain surgery, right?