But in my understanding, it is.

Debit cards and credit cards are both from the perspective of banks.

Borrowing is paying, borrowing is income.

The salary card belongs to the bank to save money for individuals. For banks, money can only go out and there is no income.

As for credit cards, you need to pay back every time you use money. At the same time, the bank will get the corresponding income such as interest, so it is called a credit card.