I imagine there are a number of those out there, but I've taken many BNPL deals that were zero fee, zero interest. It truly worked out to be the exact same cost whether I paid upfront or took the BNPL.
I imagine the BNPL people made their money from the same kind of CC fee models and from customers who ended up not being able to stay within the 0% timeline. From my memory it usually had some big fines or interest rates if you couldn't make the payments.