"As you can see on the example of Rami Ismail, keys are legitimate, because they come from the developers," Maciej Kuc, head of PR at G2A, tells me via email. "No one else is able to generate game keys."
That's not to say they're excusing the behaviour, however. They just don't see it as their responsibility.
"We are sorry that there are people who are swindling keys and pretend to be YouTubers, but this is totally different situation than someone who buys keys with stolen credit cards," Kuc explains.
"And in this situation most marketplaces would do nothing, but G2A offers G2A Direct - a developer support program from which Rami Ismail can get up to a 10% fee from the sale of his products by any third-party sellers, not to mention a great number of other interesting features."
https://www.pcgamesn.com/vlambeer-pirating-g2a