Actually they often don't. In the US, we had the Rural Electrification Act (https://en.wikipedia.org/wiki/Rural_Electrification_Act) that brought electricity into rural areas, but these places often still have wells, septic tanks, and gas tanks.

The government doesn't build water, sewer, or gas in many parts of the country! Where I live, less than an hour from DC and maybe 5 minutes from a Whole Foods, we don't have gas lines at all, we use propane and fuel oil. We got public water and sewer only in 2015, and each house is paying off a $30,000 assessment for that. Most of the areas around us are reliant on wells and septic systems. Ironically, we have had fiber since 2008 or so. As to electric--most of that was built back when labor was relatively very cheap and tons of people were unemployed. We couldn't build the national electric grid today, for the same reason we couldn't build the New York subway today.

Because the ISP corporations have sued the government (successfully) when it's attempted.

And 'successfully' includes a completed lawsuit and/or dragging out the proceedings so long that it costs the taxpayers too much to continue.

The Government does not build those.

ISPs will sue saying the government should not compete with business.

With few exceptions, the government doesn’t build or operate power lines in the US.