That's literally the point - this behavior has always only been legal insofar as the government (the Executive branch) has not been criminally prosecuting Amazo

That's literally the point - this behavior has always only been legal insofar as the government (the Executive branch) has not been criminally prosecuting Amazon for selling used-as-new or outright fakes. Biden has been a substantially more pro-consumer president and he has given the FTC and CPSC real teeth to crack down on this stuff. This is incidentally why the recent SC ruling shooting down Chevron deference is so devastating.