Consumers shopping at big box stores happens for a reason; it saves them time and, at least in the short run, it saves them money. Big box stores offering excessive variety happens for a reason; they're trying to be all things to all people, and ultimately, having more different things on their shelves is an important part of their image as a one-stop-shop, and therefore a big part of how they compete for customers. Customers tending to just by the cheapest thing also happens for a reason. Having ended up in a store with excessive variety, and with no shopkeepers who know the product well enough to make any useful recommendations, just about the only concrete things they can reliably compare by are price and feature list. Manufacturers making cheap gizmos happens for a reason. They know that this is what consumers ultimately end up doing, so they realize that their job is to cram as many bullet points onto the back of the box as possible at as low a price as possible. They also know that consumers know that they do this, which is why they subvert what few heuristics consumers have left for trying to discern quality by doing things like sticking metal weights into the product for no other reason than to make it feel heavier.

etc. etc. etc. If there was ever a backstop to limit these forces, it was the specialty shop with the knowledgeable proprietor who had years or decades' worth of experience with every single product or brand on the shelves, and heard back from their customers when things turned out to be cheap crap. But nobody's shopping there anymore, because just picking something up while you're already at Shopko will shave your time spent running errands by 45 minutes, and nobody's shopping at their website, either, because paying 8 moneys to ship something that only costs 20 moneys doesn't really make any sense.