The latest beta of iOS 12.3 includes the new TV Channels feature allowing you to subscribe to individual cable channels. Sadly it is not yet available in Australia.
Apple TV Channels is due to launch next month (May 2019) in the US with popular services such as HBO, Starz, SHOWTIME, CBS All Access, Smithsonian Channel, EPIX, Tastemade, Noggin and new services like MTV Hits, with more to be added over time around the world.
With the current beta users can only subscribe to Showtime, Starz, Smithsonian, and Tastemade.
The service will allow you to subscribe to Channels from within the Apple TV app using your Apple ID and without the need to create additional accounts with each provider.
You will be able to subscribe to individual channels rather than having to sign up to an package including channels you don’t want.