The book, "Heritage and Destiny: Reflections on the Bell System in Transition" by Alvin Von Auw offers a different perspective on this issue.
A key item was that the monopoly and telco policies were established by government regulators. Their goal was to provide universal service by cross subsidization. The very basic entry level telephone service was purposely priced below cost to make it as affordable as practical, while optional service items, such as extension phones and long distance, were priced at a premium to offset that loss.
Divestiture was, in essence, a court ordered end to those policies.
Technology improvements over the years has rendered some of the above book moot. But I still recommend it as it gives us a good history of the times and a different perspective.