Well, there wasn't a huge incentive for the biggest players to actually fix the problem. As long as Amazon was able to push the cost of returns to others, they only cared just enough that it didn't hurt their brand. This goes for both bad products and poorly advertised products.

Now that there have been some recent rulings that Amazon is liable for defective products they sell[1], we might see a difference as they put actual effort into it since it's more directly related to the bottom line of their e-commerce business.

1: https://www.businessinsider.com/court-rules-amazon-liable-de...