AT&T owns WarnerMedia, formerly Time Warner, which owns cable networks, movie & music studios. Most of the entertainment Americans consume are owned or produced by AT&T or a subsidiary.
Regulatory capture has turned the internet into a de facto monopoly. There won't be any new players because they can be sued or acquired long before they become a threat. Our only hope is for regulations that prevent ISPs and media companies from being under the same umbrella.
So they absolutely have some control/influence over a sizeable portion of the media that we consume, even the segments they don't technically "own".