Why is Australia described as the flattest continent?

Australia is described as the flattest continent primarily due to its vast, low-relief plains and the extensive, long-term effects of geologic time on its landscape.123

Several key factors contribute to this characterization:

• Erosion and Weathering: Over immense periods, the forces of wind, rain, and heat have acted upon the continental mass while it remained elevated above sea level. This prolonged exposure to weathering and erosion has significantly worn down the terrain.23
• Low Elevation: The continent lacks high mountain ranges compared to other landmasses. Only 6 percent of Australia is above 2,000 feet (600 metres) in elevation, and its highest peak, Mount Kosciuszko, reaches only 7,310 feet (2,228 metres).34
• Geologic Stability: Australia is positioned at the edge of a zone of significant and geologically recent earth movement, meaning much of its surface has remained relatively stable and undisturbed by the dramatic tectonic uplift seen on other continents.3

As a result, the landscape is dominated by vast plains, plateaus, and low-lying basins, reinforcing its status as the flattest continent on Earth.153