Yeah, AT&T Fiber never completely stopped expanding but they did slow down quite a bit in 2020, I think. They'd said from that point forward that they would be much more selective about where to rollout. But then they just announced that they plan to put their foot on the gas again in 2021 and expand to at least another 2 million homes.
I switched from Comcast to AT&T Fiber (via a reseller, Toast.net) back in Sept. I got lucky and got their latest wifi 6 gateway and love it. It's a great service, more reliable than anything I've had before (well, outside of the Christmas outage due to the bombing here in Nashville by the AT&T building downtown). I pay a flat $45/mo for standalone 60/60 service with no data cap. The price should never increase; Toast.net doesn't do promo rates and my plan is grandfathered and no longer sold.
I don't know if I'll ever leave the service as long as I continue to live in this house because I doubt I'll ever see another ISP available here that's as good for the same or less money.