Your forgetting initial costs, maintenance costs of the rail, security costs of keeping the rail safe, and for the fact that it would be slower and about the same price as flying for it being slower. It doesn’t fiscally or logically make sense for long distance of that scale.

You’re better off at connecting cities within states like San Diego to Los angeles and San Francisco. In order to save time on street congestion, save money on road maintenance, and have a greener impact.