Slim pickings (for the rest)....
All you need to know about phone system in Mexico (actually, all you need to know about Mexico) is that Carlos Slim is the richest man in the world making money in one of its poorer regions.
But over the border in the land of the free, Verizon and AT&T pretty much have a duopoly that's reflected in prices higher that in Europe.
Corruption isn't the issue (its endemic in Mex) the system is what's wrong. Where governments dish out licences to print money, no surprise when the recipients do so left to their own devices.
Before the curbs on roaming charges, who'd have thought we'd be grateful to the EU.