Correct me if i am wrong if you watned a 1:1 scale of Astralia , that would be way too large to store

Some computer games use compressed space. For example, there is scenario in Age of Empires 2 where you control the vikings crossing the Atlantic to reach the Americas. You have the Atlantic ocean on the map, and you have little viking boats on the map, but the boats and the ocean are obviously not at the same scale. The relationship of the scale of the ships and the scale of the ocean can be expressed as a ratio, probably around 1:2000, give or take an order of magnitude.

A lot of other computer games do not use compressed space. Everything is at the same scale. You could say that the ratio between all objects in such a game is 1:1.

What the OP probably meant is something like, is there a map of Australia with enough detail that you can use at a human scale, for controlling a human-sized avatar? The OP's question is poorly worded and ambiguous, but there's no reason to accuse the OP of trolling.

Microsoft Flight Simulator tries to do the whole world at 1:1 scale, and doesn't do all that badly. It took a lot of effort to create all those assets from various data sets. And there's a good engine to fetch and display them seamlessly.

This UE project looks impressive too: