Well, somewhat. But Amazon doesn’t vouch for its supply chain since it “commingles inventory” that various vendors ship to its warehouses. So even if something is “sold by” Amazon there’s risk it’s counterfeit junk.
Some flea market sellers, unreliable as they can be, have an advantage here: many sell under their own brand, even if you’ve never heard of it. In contrast, if you seek out a known brand on Amazon, there’s the risk of fakes. Every product listing on Amazon carries a set of risks.