I worked in mobile telecom in the 2000s when MVNOs (Mobile Virtual Network Operators - basically resellers) were the next big thing. Companies like Amp'd or Boost or Virgin Mobile would resell another carrier's network with their own branding and personality. One of the reasons there was a disappointing uptake in MVNOs were that the carriers were stubbornly refusing to become wholesale dumb pipes. The only one that seemed consistently cool with it (perhaps out of desperation) was Sprint, which is why most MVNOs that you've heard of use Sprint's network. So if any of the carriers took this route of differentiation, it seems like they would be the one.