That works fine in nowheresville like the Nevada desert. Unfortunately, the bulk of America east of the continental divide is too populated to legally pull that off in any reasonable amount of time.
Much of the cargo lines through much of the country are pretty flat and straight. Tracks and such would have to be upgraded, but doable.
Bigger problem though is my previous mention. They own the lines, so passenger rail is a second-class citizen.
Probably the most sobering part. This is exactly what they're doing, as Muskrat is too dumb to understand how they work (and don't.) Meanwhile, the 19 year old kids accessing old COBOL systems are trusting hallucinating AIs to access them, but since the kids don't actually have the knowledge and wisdom of how COBOL works, they'll blindly trust the hallucinations.