There are a lot of frauds that are taking place with respect to cards and banking accounts.
The leak of sensitive details related to the card or the bank account can lead to a financial loss for the individual.
The two factor authentication is nothing but an addition of another layer of security for a transaction.
For a credit card the basic details of the card and the CVV is the first line of security.
In addition a one time password sent to the mobile phone linked to the card becomes an added layer of safety as only the cardholder is supposed to have this.