AT&T holds the position of the largest fiber internet provider in the United States, with a network passing more than 28 million locations. Its integrated wireless and fiber infrastructure enables compelling bundled service offerings that reduce churn and increase average revenue per user.

The company's extensive fiber backbone directly supports its 5G wireless network, providing a differentiated network quality advantage over competitors who rely more heavily on third-party backhaul. This vertical integration in network infrastructure is a structural competitive moat in the US telecom market.