It makes products more “affordable” (emphasis on the quotes) by spreading the payment for them over multiple salary cycles. That TV you didn’t buy because you c

It makes products more “affordable” (emphasis on the quotes) by spreading the payment for them over multiple salary cycles. That TV you didn’t buy because you couldn’t afford it? You told yourself you don’t need it, but now that you can mechanically pay for it, you “need” it so you’ll buy it. It also allows the sellers to increase their prices or even simply upsell without pricing out their own consumer base.