Many comments assume (quite naively) that Big Marketplaces have no idea that it happens, and are fooled by shrewd counterfeit sellers who are always one step ah

Many comments assume (quite naively) that Big Marketplaces have no idea that it happens, and are fooled by shrewd counterfeit sellers who are always one step ahead. I suppose it is a complete fantasy, and those marketplaces have precise analytics on how big is the market of selling crap to illiterate consumers. If they voluntary abstain from that, and ban swiftly, they'd simply let competitors feast on that crowd, which would be bad for business™. Therefore, the handling of negative reviews, refunds, and fraud detection will always leave just enough margin for cheap counterfeits to be sold. As long as they both profit, it's a controlled dumpster fire.