Damn, their strategy of relying on the inertia of their reputation is working just fine, I just switched to them from fine-but-not-spectacular AT&T when I needed to add on a couple new phone lines. The price was about the same, and so far to me network performance seems better, but probably a lot of that is just placebo effect.
Is t-mobile actually usable now? I’ve tried them 2-3 times over the last decade and urban performance was generally acceptable (though even then with weird dead zones that made it tough to use) but it would always quickly fall over any time I was beyond suburban areas.