Their source is an author that doesn't know what money laundering is. What he described is just a way to cash out a stolen card (fraud).

Can you tell me how you can laundering, say $100K in cash via Amazon? If you already have it on a credit card, you've already laundered it.

While in the US and Canada, "credit card" is the main method of payment, large parts of the world in which Amazon operates offer additional payment methods such as bank transfers, with credit cards offered as secondary option but not owned, let alone used, by large portions of the demographic.

If you already have a credit card, you're indeed almost certainly already good to go.