[digiown]

Individual used pieces of clothes are not nearly the same as unsold or returned (~new) available in bulk quantities.

[SpicyLemonZest]

They aren't, but the problem is even worse for bulk quantities. A local charity operation or thrifty individual might find a use for a couple random articles of clothing; a pallet carrying 2,000 copies of the same unpopular skirt is worth less than zero to anyone but a large clothing distributor.