They do compete at least in some places in cable television.
When I lost a job with a company I'd worked with for 12 years, I bounced around a bit afterward. One of the jobs I did for a while was door to door selling and offering of AT&T U-verse, which is their cable television platform. They also did the dreaded bundle, and wanted us to offer it at least as an option- tv, phone, and internet.
I know they don't reach everywhere. For instance, though I haven't checked in a long while, I can get AT&T "U-verse" internet, but not the cable tv.
If I'm not mistaken they bought in to one of the satellite dish companies as well. Either DirecTv or Dish Tv.