Voice traffic is just bits
My Internet service provider is Verizon, a "telephone" company. Their traditional business is selling a specific application: voice telephony. But, if one has sufficient bandwidth, they can carry on voice conversations using VOIP and do not require separate "telephone service." Similarly, with sufficient bandwidth, one can download video entertainment without the need for a separate "cable TV service." The bundling and separate pricing of services with connectivity made sense when a dedicated connection was necessary to ensure sufficient quality of service, but today this model seems a bit like the water company charging different rates for "drinking water," "dish-washing water," and other water-based services.
Similarly, on the Internet, voice service can be provided by anyone, not just a phone company or a cellular phone company. Voice can also be integrated into other applications, such as the click-to-call feature on Google maps for local business.