I just assume that any of this cheap unbranded garbage is filled with shit that's toxic. The Chinese companies making this stuff has no reason to care. They can't be held liable for anything.

Why would Amazon be any different in practice?

Being a US company doesn’t stop them from being filled with imitation/knock-off goods from fly by night companies.

us companies are subject to lawsuits from us citizens and government

In theory. On the ground - they just provide a market hall, with no liability and fitness of purpose implied.

The same unbranded, zero QA, zero accountability products direct from China being sold on Amazon are also a problem. The only difference with Amazon that puts them like a single rung above Temu and Shien is that they also sell proper branded, non-counterfeit items (though my understanding for a while has been that counterfeits do end up getting mixed in with legit items).

With the federal government the options are do things slowly or not at all.

Not true during crises, eg covid related manufacturing.

Aaaaaaactually…