I also haven't received any counterfeit ever. I have 400+ orders a year...

I think what a lot of people qualify of counterfeit (not saying OP does here) is people buying cheap no-brand Chinese garbage and receiving cheap no-brand Chinese garbage and not being happy with it.

Or buying, for example, electric toothbrush heads at half the cost they are in the supermarket and then being surprised when they turn out to be counterfeit.

But that's the other aspect to commingling, I guess - you might pay full price for the real deal and get a fake, due to bad actors' stock being commingled, but on the flipside a punter who's paid an unrealistically low obviously-fake price might actually get the real deal, adding an air of legitimacy to the bad actor.

There’s definitely counterfeit stuff, but it’s much more common in some categories than others. USB cables and chargers, SD cards, USB flash drives for example are commonly counterfeited (e.g advertised as made by Apple or SanDisk but actually being ‘cheap no brand Chinese garbage’). Many wouldn’t even realize it because the products usually still work, but have major defects like less capacity than advertised or being built much worse.

No, I know loads of people having bought SD cards from reputable brands at full price, only to receive a fake one in the mail. You don't notice until you're using the card and your gopro writes too fast to it. I don't like the victim blaming of your post.