Looking at Tmobile's plan, https://www.t-mobile.com/cell-phone-plans I'm shocked at how low their price is for 3 phonelines. $90 essential plan is all I need. Similar plan on ATT would cost me at least 30%+ more.
I doubt T-Mobile would be selling its services for less if it had the same coverage Verizon and ATT did, so effectively T-Mobile is selling an inferior product.
Both Verizon and ATT tried to pull off a Comcast and tried to go vertical by acquiring content makers to avoid being just a dumb pipe, but they both failed miserably and ended up with a ton of debt.
ATT failed much worse though. They paid $50B for a satellite TV broadcaster in 2015. It was already obvious that streaming was the future. Either extreme corruption or astounding incompetence.