Ann: Appendix 4C with ASX Direction Included, page-112

Because many of these interactions take place through third parties. External sites buy/sell skins or currency (or provide a marketplace for others for a fee) so they would certainly incur loss if they suffered a chargeback. In a way they do have inventory, because they own finite amounts of whatever they're selling.

It is possible to phish someones details, buy cosmetics from a third party website with a stolen card, and then sell those cosmetics to a different third party website with the payout going to the scammer's own bank account. When the stolen card is discovered and rectified, the first third party seller will have lost the value of the cosmetic item for no return.

I'm not saying KYC solves this problem, but it's not valueless either.