Because it greatly lowers the risk that AT&T will need to write off the debt for your phone and sell it to a collections agency for pennies on the dollar.
It’s the same difference as a home mortgage vs unsecured credit card debt: When the threat exists that the lender can repossess your home if you don’t pay… they don’t have to worry as much about you not paying your mortgage, so they can offer a much lower rate.
It’s the same difference as a home mortgage vs unsecured credit card debt: When the threat exists that the lender can repossess your home if you don’t pay… they don’t have to worry as much about you not paying your mortgage, so they can offer a much lower rate.