> This is a regulatory problem
This is a consumer problem - "you get what you pay for."
If you want to buy something from a retailer that gives a shit about their wholesalers, shop at a local superstore for whatever items your looking for and eat the difference in cost.
> If Amazon was a corner hardware store it would have been fined multiple times and the owner might well have been jailed by now.
If Amazon was a corner hardware store and not a marketplace, they would have been run out of business by all the customers returning garbage and counterfeits they bought from them. But that's not what Amazon is, they're ostensibly connecting buyers to sellers and providing logistics - not behaving as a retailer that selects their wholesalers and manages their supply chain besides getting shit from point A to point B.
What Amazon shouldn't do is have it both ways, either they're an Ebay-esque digital flea market where everything is buyer-beware, or they're a retailer who is responsible for the garbage on their shelves. They don't want to be either, and if there's regulation to be had, it should focus on that difference (as well as regarding their own products - you don't see flea markets driving their merchants out of business by stealing their products and undercutting their prices, while stores can stock generics alongside their curated shelves).