The article mentions that they only buy returned overstock items from manufacturers at steep discounts. So this stuff was getting made anyways.
Not quite true. From the article:
> Almost half of its products are leftover goods that manufacturers couldn’t otherwise sell.
I bought a suitcase there and used it to travel the world. I would definitely consider it "useful".
The problem isn't that they sell no useful items, they just sell so many items that even if a small percentage (it's not a small percentage) are destined for landfill then they're creating an astonishing amount of waste.