I’ll add my parents to one of those many. My parents had ATT a while back and it wasn’t too bad while they were only paying for 20 mbps. There wasn’t any downtime and they averaged like 17 mbps, so not bad for what they were paying for. As my parents got more into streaming they decided they wanted to upgrade and ATT was having a spectacular deal on 75 mbps, so they decided to upgrade. Well, for whatever reason, after they upgraded they were still only getting about 17 mbps on average. They had ATT come out 3 or 4 times to try and fix it with no results. Eventually ATT told them that 17 mbps was withing their acceptable threshold for their plan, because it’s “up to 75 mbps” and there’s no guarantee that they will match that speed.
So my parents cancelled their service the next day and had Comcast come out. Comcast had a plan for like $10 more a month for 150 mbps, so that’s what they went with. They very rarely have any downtime and they usually get about 140 mbps on 5 GHz and like 80 mbps on 2.4 GHz. So they’re happy with it. Sometimes they even get above the expected speeds on 5 GHz (I’ve seen it up to 183 mbps), 2.4 Ghz isn’t great (almost half the speed of what’s advertised) but almost all of their stuff will do 5 GHz anyways so they don’t really care.
If there were other reliable options where I live I wouldn’t go with either of them, but seeing as how they’re pretty much the only choices, I’d rather go with Comcast because at least it works. I’d never go with ATT.