Add to that that the Hyperloop is incompatible with regular rail.
If you build a highspeed rail connection between two cities, you can start by just building highspeed tracks on the straight, empty areas of the connection where you get the biggest benefits, while letting the train run on regular rails in between. So while building the track, the travel time will be gradually reduced as more and more of the track is completed. In the cities themselves, the train can use regular tracks (since highspeed travel probably won’t be a thing there anyway due to space restrictions), and it can also use the regular railway stations. This allows you to directly connect the rail service to other trains without having to build separate stations with potential shuttle services in between.
Add to that that the Hyperloop is incompatible with regular rail.
If you build a highspeed rail connection between two cities, you can start by just building highspeed tracks on the straight, empty areas of the connection where you get the biggest benefits, while letting the train run on regular rails in between. So while building the track, the travel time will be gradually reduced as more and more of the track is completed. In the cities themselves, the train can use regular tracks (since highspeed travel probably won’t be a thing there anyway due to space restrictions), and it can also use the regular railway stations. This allows you to directly connect the rail service to other trains without having to build separate stations with potential shuttle services in between.