A major misconception -- largely advanced by legacy incumbent telephone and cable companies – is local governments build Internet infrastructure because they want to compete with the incumbents. Competitive markets are those characterized as having many sellers and many buyers. That’s not possible with Internet infrastructure due to high barriers to entry and high ongoing operating costs.
Local governments build Internet infrastructure not to engage in market competition with incumbent legacy cablecos and telcos. They do so in response to market failure where the incumbents cannot profitably serve local needs. Lacking sufficient potential profits, the incumbents naturally aren’t going to be inclined to upgrade and build out fiber networks.
In terms of those left off the Internet “grid,” the scale of this market failure in the United States is substantial. The U.S. Federal Communications Commission (FCC) estimates about 19 million Americans live in homes where Internet service isn’t available.