Yeah, T-Mo may fighting a better fight, but their security issues dog them. Maybe the average consumer doesn’t care, but I find it hard to champion a brand that gives such a half effort to protecting their customers’ information.
There is no perfect carrier; the best you can do is pick the one least likely to sell you out or get hacked today.
Security breaches are always a matter of when, not if. If you think that AT&T, Verizon or any of the 20 MVNOs that interface with their systems don’t have similar vulnerabilities, I have a beautiful bridge in Brooklyn with your name on it.