I'm suggesting there is a significant risk, and anyone reasonable at Amazon would account for it. There's enough users (tech savvy, or heavy researchers as you point out, and ultimately some portion of casual customers) who will have a negative experience and potentially be skeptical of all purchases - major or minor. Amazon will certainly incur reputational and real return/handling costs.
It seems fairly implausible to me that Amazon would make the decision to say "Yeah, while tech savvy and discerning customers, and some portion of casual users will discover the scam, we just make so much money from fake thumb drives that it's worth it to destroy our reputation with that subset since a significant portion may not notice or ultimately associate Amazon with selling low quality products." All while we see the listings for these items get removed nearly as quickly as the pop up. Doesn't add up.
A fake (say) Gucci handbag is made with less premium materials, but only savvy consumers would notice once it arrived. You would not necessarily know from the product details on Amazon, but may have a clue based on price.
Whereas 1tb thumb drives have been sold for years now on Amazon and Wish and what-have-you but only recently did real 1TB thumb drives come into existence. Real Gucci bags have been around for decades.
Any 1tb drive which costs less than hundreds of dollars is fake. Full stop.
Only if you are actively verifying the data. Im pretty sure most people would just look at a file listing and consider it stored.