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.
Sneaker counterfeiters generally don't care all that much about pass authentication checks. For shoes, and most clothing, they care more about time to market (getting their fake out before or near release date) and price point. If someone is wearing fake shoes, unless they're outlandishly fake (there were some hot pink fake yeezys I've seen more than one), you mostly likely won't be able to spot these imperfections from a distance. Also, unless you're in the niche you probably won't care if they're real or fake. I'd liken this to hanging prints of famous paintings; people like the look but might not want to shell out for a Picasso.
I work with shoes on a daily basis and have done/do auth checks.
Yeah unfortunately this is true. There are absolutely fakes that get passed through StockX/GOAT/eBay and even sneakerheads wouldn't guess. Some are even made on the same production lines with the same staff, etc, according to some people in the rep industry (yeah that's weaselly, sorry). I have disputed purchases when I got inauthentic items but they were fairly obvious.
