Nah you're just using the bank's money instead of yours which you would've spent anyways.
The benefit here is your money is in the bank, accruing interest.
Suppose you spent 100K in January. Cash or debit - it's instantly gone. Spend the same amount with a credit card, settle on February 1st, you'll have earned 334LKR in interest for the 100K you had in your savings account for the month of January (4% annual interest).
Same goes for 0% EMI payment plans, paying monthly installments instead of a complete payment earns you interest.
