The Mad Max franchise is set in future Australia as the country is experiencing societal collapse caused by war and shortages of critical resources. Over the course of the Mad Max movies, the environment rapidly devolves until its most dramatic portrayal in Fury Road, when the landscape resembles little more than a barren wasteland. In the original Mad Max, there’s still some semblance of law and order, but matters quickly devolve further, leading to questions of how everything became that way.

https://screenrant.com/mad-max-movies-world-apocalypse-wasteland-oil-explained/