Amazon, in many cases, is not the seller. They are simply an online market. The reason you see the same products across multiple websites is because it is the same product. Doesn’t really have anything to do with shitty products although that’s what a lot of people do. They take advantage of Amazon’s monopoly on the market and sell products for hundreds if not thousands of dollars % mark ups. The reason it’s still cheaper on Amazon is because of the aforementioned price fixing.