BNPL is a convenient way to purchase an item that may not be within your immediate budget. Since your card's available credit line doesn't determine your eligibility, you can still use BNPL even if you've maxed it out.
It's easier to get approval for BNPL. Compared to more traditional methods of financing, such as taking out a personal loan or applying for a credit card, there are fewer qualifications to meet for BNPL.