Rail can be used to make routes densify though. Air travel can never do this. The cost of rail has to be thought of in the context of an investment in a city or

Rail can be used to make routes densify though. Air travel can never do this. The cost of rail has to be thought of in the context of an investment in a city or country (this doesn't mean 'go crazy building HSR' like some countries but then again many countries have no problems with approving road megaprojects that are terrible ideas so why not rail?). This is actually true of road infrastructure too, but there are a lot of negative externalities to roads that don't apply to rail.