I'm not sure about pokemon but for magic:the gathering, the oldest and most valuable cards have a fair amount of quirks which are hard to replicate, due to the

I'm not sure about pokemon but for magic:the gathering, the oldest and most valuable cards have a fair amount of quirks which are hard to replicate, due to the different printing techniques (as well as some effects just due to the age). There's still fakes but they mostly scam unaware buyers (and usually for lower value cards). People who just want to play the game will often buy professionally made 'proxies' which are just as functional as the cards but don't have collector value (and aren't legal in events sanctioned by the designers, since it amounts to copyright/trademark violation).