Electricity, gas, and water work as utilities because to a first approximation, the only competitive access is price. One thing regulation can do is drive prices to an acceptable place (often not the lowest price, but a satisficing price).
But that is not the only axis of competition for Internet service. Nobody knows or cares what the quality of their gas service is, but most people can tell you how fast their Internet connection is, and not everyone wants the same service.
As I pointed out downthread, when telecom was a regulated utility, we didn't even have competition in telephone handsets.