On AliExpress I see things like 64 TB (no, not GB!) USB flash drives for less than 10 euro, obviously a scam. I also see less spectacular products but still good looking deals, but without a brand name so you can't search the web for reviews.
On Amazon I never see products like that. That's why I prefer Amazon (and Coolblue and bol.com in Belgium).
I see this kind of fakes on eBay or Amazon all the time. It's even harder to report it than on AliExpress and I never had an obvious report of fakes upheld (AND eBay warns they will forward your identity to the seller. Great thing if the organised crime is involved in this)
Case in point, fake 2TB Sandisk ExtremePro microSD:
If you believe that, I have some USB storage to sell you. Huge capacity, barely used. I keep my inventory in storage under this bridge, which I also happen to have for sale. Interested? ;)
AliExpress is full of fakes and weird things but what it has going for itself is customer support. They'll return you money pretty much in every single case. They're so pro-consumer you could easily scam sellers out of things you buy really. I disputed multiple things in last 5-8 years and I've always either got a new item or a full refund. I don't order that much from there but if I want to buy something cheap I know is made in China anyway, I'd go for Aliexpress
On Amazon I never see products like that. That's why I prefer Amazon (and Coolblue and bol.com in Belgium).