The problem is that Amazon, Walmart & friends have said the "we are a platform, not a retailer" magic incantation, which means that through the power of friendship and unicorns they are now suddenly no longer responsible for the stuff they sell.

And the "retailer" on record is of course not a real company. They'll just pay some third-party to file a bunch of paperwork in Delaware, pay the $110 fee, and let it go bust if anyone tries to investigate it or make it liable.