The canonical example is person A buys some risque item, their partner sees the credit card statement says "what is this?", so then person A denies they made the purchase (because they are embarrassed), says it must be fraud, so then it gets charged back on the credit card.
They do not have SMS OTP confirmation for bank card purchases? It is much more difficult to deny anything when there is a record of delivered SMS message along with phone identifier and precise location.
User uses a credit card, either a legitimate one or a stolen one, to buy access to a site. They download all the content that their purchase gives them access to. Then they (or the card's legitimate owner) initiate a chargeback. They "lose access to" the site but they already have everything that's there for free, and they add it to their library of other stolen content.