I think we both know what's usually happening: people in an area who, as a whole, are rural enough and poor enough that the economics don't really pen out well. And I'm sure said corporations would be happy for the local government to pay the cost of running those lines out -- if that's not happening, ask yourself why those local governments don't want to pay for it either.
Now if you want to say, "well I don't care if it scales badly, the federal government should just subsidize it until it works", that's your prerogative. But another option would be to encourage zoning and similar rules that impact how people live to change towards better scaling of infrastructure and services, so that spending on these kinds of things is more sustainable and fair.
people here don't understand how large USA is -- connecting every corner with copper/fiber, with all the intermediary networking devices means tax money...
We also paid $42 billion in taxes for ISPs to roll out broadband access in a 2021 bill, and it hasn't connected a single person to the internet
Before that, we paid $400 billion to ISPs to do the same thing with the same results