I feel like it's not a knowledge problem to the counterfeiters, but more of how the economics work in counterfeits.
A lot of people are ready to pay for a 20$ bag on AliExpress and probably never seen how a real Louis Vuitton bag feels, so they don't see/feel the difference. Same thing for jewelries, watches, shoes, etc. You see a lot of fake Yeezy (for example), and you can probably get a similar enough shoe to the real one, but it'll cost 100-200$, and most people are not ready to pay this price for a "fake".
On r/repladies, I've seen girls pay 1200$ for "fakes" that are very similar to the real product, at a certain point that only a handfuls of people will see the difference.