> The general public hasn’t the faintest idea how to differentiate between a safe product and an unsafe one, and they shouldn’t have to

The problem being that a marketplace platform with millions of small sellers has no reasonable way to do this either.

Then, that marketplace has no viable business. Society does not owe them anything. Seriously, if your business model requires you to sell illegal stuff, then your company does not deserve to survive. That’s the basics of regulation.