Brisbane

I think if you were commuting from Brisbane to Taiwan, the length of trip would come into play also. Perth to Taiwan would make more sense. It's slightly closer and in the same time zone. 😁

To answer your unstated question: suburbs with rail links see those rail services enthusiastically used. So, usage is not the issue. It's the upfront costs of establishing links, coupled with how long it takes - a decade or so. Our politics is just not well equipped for long term big infrastructure projects. The chances are high that the opposition will be in power to take the credit for the project's completion, or they'll blame your party for the bad project when they get in and the costs blow out. Or, they kill/maim the project anyway.