Earlier quoted context omitted.
I don't think this is correct. It's far more difficult to compete as a cell phone service due to FCC regulations. It's a government granted mono/duopoly. I expect to see cell service remain complete shit. I don't expect these per-website apps as they exist now to be widely used.
This needs a lot of expansion. Which FCC regulations are keeping competition out?
I don't think that's the main difference between the US and say... Germany though. I'm pretty sure German carriers are required to sell each other access to their networks under reasonable and non-discriminatory terms, making it fairly easy to become a carrier without building a bunch of cell towers. The phones are all GSM and almost all unlocked, so it really is as easy to switch as getting a SIM from a new carrier.
This actually appears to be a case of more regulation, applied to just the right spot resulting in more competition. Politically, I'm not usually in favor of a lot of regulation, but it looks like it works in this case.