The magical thinking with less regulatory power = more competition with regard to utilities like last-mile internet comes down to 1) infrastructure cost and 2) lack of access to shared infrastructure.

For most potential players, it simply costs too much to even think about entering the market. Truly unregulated free markets are great in theory, but are instantly distorted when you take things like reality into account.

Part of what the recent net neutrality rules did is ensure that power utilities must lease pole/conduit access to internet utilities at the same rates they lease to cable tv and telephone utilities. This helps reduce cost to enter the market.