2% monthly churn is not low. That annualizes to ~25% which is significant. The cost per acquisition of getting a new customer is actually quite high so their churn numbers definitely hurt them.

When there are only 4 carriers in the US, it doesn't really matter. AT&T will lose a customer to Sprint, Sprint loses one to T-Mobile, T-Mobile loses one to Verizon, and Verizon loses one to AT&T. No one is getting rid of their cell phones.

The point is they still have to spend the money to make keep their flows positive otherwise they'll bleed customers to the other 3 and die eventually.