It is absolutely 100% possible, it's already happened in countries where regulators force networks to allow use of unlocked devices or even ban the locking of devices. When you stop locking you get an environment that's a lot more like the PC industry and the ISP industry: Does your ISP care what operating system is on your PC? The reason they wouldn't want to admit that it's possible is because it involves competition, i.e. it involves hard work to win customers instead of just lazy milking of customers. The network operators in the USA seem to be the laziest of all. No large company ever allows competition to increase if they can stop it. They have to be forced into competitive environments, and that's why we need strong government regulators to do the forcing.