Klarna makes the money with the device that’s either returned, or the balloon payment at the end. Klarna owns the device unless the customer submits enough payments to buy out the lease, so they are banking that they will return the device.
An iPhone 17 Pro after 24 months of leasing is a total payment made by the customer of $767 for an iPhone that was worth $1099. At the end of the lease when the customer returns the iPhone, they now have both the iPhone (whatever it’s still worth, let’s just say $900 after depreciation) AND the $767 in money from the lease. That’s $1667 in total value now in Klarna’s hands, and that’s all without any fees or interest, too, so that’s $568 in profit to Klarna. And if the customer decides to pay off the iPhone to eventually own it, then it’s simply a wash for Klarna.