I felt the same way at first. Traditional BNPL schemes were very predatory. However, Klarna (and others) appear to be playing approximately the same game as the traditional credit card processors. They charge transaction fees that are roughly the same as credit card processors, and like credit cards their customers don't pay extra if they pay their bill on time. Klarna, in particular actually appears to give customers interest free time.
The difference, for consumers, is primarily that a Klarna account is much easier to get, and it isn't universally accepted. From a merchant perspective, depending on your payment provider, you might already be able to accept Klarna, and it appears that it mostly works like a credit card. It's even possible that charge backs are less of an issue, although it does appear that transaction fees are not given back in the case of a refund.
Personally, I am all for competition when it comes to payment networks. Visa and Mastercard are both devils. More competition for them is good for all of us.