Yes, for people who intend to keep their iPhones, this is a way to spread out the cost over 2 years, interest-free.
But that option has always been available: you can buy an iPhone on a 24-month payment plan that's interest-free.
What's new about this Apple Upgrade program is the lease part. Leasing cars costs you more in the long run, but is tempting because it gets you into a new car every 2-3 years for a monthly payment that's lower than the payment you'd pay if you purchased the car with a loan. The Apple Upgrade program appears to be much simpler and more transparent than a car lease.
I guess I'm glad this option exists for those who might benefit from it, but it's not for me. With prices going up, I'll be replacing my iPhone every 3-4 years instead of every 1-2 years as I've been doing until now. So the 24-month interest-free purchase plan is the best option for me.