Solar is cheap and abundant during daytime. It has zero power at night. Coal/gas/nukes are more expensive, but runs 24/7. Batteries are getting cheaper, but are still not that cheap.
In areas where there are gas transmission lines, sure. Large portions of the country don’t have that infrastructure built out yet, but do have rail lines which provide coal.
It’s also a timing/capital issue.
It will change eventually, but in the meantime people need their kWh.
I’ve never seem any analysis of feasibility for LNG (probably what you’re referring too) vs pipeline NG for things like power plants. Do we even have sufficient liquifaction facilities for that type of volume? When I hear of that kind of thing, it’s almost always liquifying for export to places like Europe.
AI/Data centers need power 24/7.