In fact, Amazon is so overrun with low quality products that I'd even go as far as saying the average Walmart product is better quality than the average Amazon product.
Amazon is AliExpress with a domestic retailer's markup. At least with Walmart I know that when they stock something on their shelves, they care about liability and bad PR.
This. At any brick-and-mortar store, the store itself takes some responsibility for the quality ("won't fail dangerously or slowly poison your children" quality, not "won't fall apart after a year of use" quality) of their products, if only because it's more clear that they'll catch some blowback from stocking illegal products in their stores.