I understand what you are saying, and yet with a different carrier, when you pay off the phone your overall monthly bill doesn't go down. There's obviously a difference (whether there might be something else that sort of balances it in a general sense on the start or end side of things is somewhat separate from that).You keep saying it but I don't think you see it......in both cases with both carriers the SERVICE PLAN is the same. You make it sound like my carrier charges an additional "phone fee" regardless of a contract or not. My service plan is not higher because of a phone just like tmobiles is not low because of a phone.
I look at the phone fee like an optional feature on top of the service plan. My bill would go down if I removed insurance but my plan would still be the same price. When you pay off the phone your bill goes down but your plan is the same price and it would be the same price if you provided your own phone.