G2A isn't more fraudulent than other marketplaces, if someones selling a game for less than any official retailer it's likely to involve fraud. G2A and Kinguin are just the biggest ones.

Regional pricing is the alternative to it being cc fraud, which I'm pretty sure still qualifies as fraud but since the publisher doesn't lose money from it it's kinda whatever. But many games are now region locked and still show up on these sites, I sure wonder why.