What he's trying to say is that if there were 198 fraudulent copies sold on G2A, but G2A also was responsible for 500 non-fraudulent sales, then Wube might have still netted a profit off G2A from people who would not have bought Factorio full price. Since nobody has ever shown that anywhere near a majority of keys are fraudulent, it is entirely possible for most games that they still make more money even after chargebacks than if G2A didn't exist. There are, however, definitely going to be games where that's not the case.

The better argument, honestly, is that G2A being unwilling to police fraudulent sales is helping the scam industry, and is responsible for us getting more Microsoft Support, Amazon Refund, etc scams in our inboxes. I do not hold the negative view most do on key resellers because most of the reason big media hates on them has nothing to do with the fraud... but honestly companies like G2A should be doing more (something) to own and police their shit. I personally think a majority of G2A's keys are legit because there are a lot of ways to legally gets keys much cheaper than MSRP. I frankly support that behavior because I'll never be a fan of the IP price controls and treating game purchases as "licenses" instead of purchases.