If something is going to be uncompetitive in any case, you strip the power to leverage that for additional control from the uncompetitive thing. Government road networks face no competition, but that's virtually never an issue because no one is leveraging that monopoly to restrict competition elsewhere, not to charge rents beyond what it takes to maintain he road network (or even sufficient to that end.)

Last mile connectivity is a natural monopoly, whether or not it is a government monopoly.