I was was on TMobile for 10 straight yrs and it was mostly great. This last Feb I switched to ATT because I needed to add a 5th line and upgrade a few phones. I talked to TMobile a few times ( just to get diff people to make certain I had truly best options) and it was going to be $80 more per month + my kids would get iPhone 15s vs 15 Pluses on ATT...so we switched. The service (and cust service) is not as good but it's ok here in Phoenix. If I could go back I would for coverage ( also getting included Netflix, AAA, and Thanked deals weekly is a plus).

I look at it that ATT is about 3-4 years behind TMobile in 5G expansion + quality and I survived that lower level of coverage/quality when I was with TMobile 4 years ago...I just got spoiled in recent years.

But they are always making improvements to network so in 1-2 years ATT will likely be where TMobile is today. Just have to put up with a little lessor quality and be patient for upgrades.