This is making my head hurt. It's not very complicated.
Generally speaking areas have exactly two land based service options, one from a telephone company (ie Verizon, AT&T, Century Link, Frontier), one from a cable company (ie Comcast, Charter, Cox, Altice). The cable company generally offers TV, internet and voice services. The Phone company offers voice and usually data. In select areas, the phone company offer TV services usually where they have fiber deployed. This applies to 90%+ of the country. Can we all agree on that?
But as with everything in life, there are exceptions. In some areas select, there are cable operators (ie RCN, WOW, Grande) that have their own infrastructure that directly compete with the big providers. These are not border areas, these companies specifically overbuild to provide alternatives. And this Isn't Comcast and AT&T Fiber at the same address, or Charter and Verizon Fios at the same address, this is two coax delivered services that offer TV, internet and phone at the same address.
I picked a random town in the Columbus, OH area. Grove City, a suburb located about 15 minutes south. Entered the zip code into Zillow, found a random house for sale and entered the address into both WOW's and Charter's service availability checker and guess what? Both companies service that address.
Yes that is rare, but is does happen where you can choose between a large cable company and a smaller one. What is even rarer is a reported situation in Florida. There are pockets of the Orlando area supposedly where Comcast overbuilt into Brighthouse (now Charter) areas