https://en.wikipedia.org/wiki/What3words says "What3words divides the world into a grid of 57 trillion 3-by-3-metre (10 ft × 10 ft) squares".
Australia moves about 7cm/year so after about 43 years a W3W coordinate no longer matches local coordinates.
It feels weird that a continent could move so much in someone's lifetime.
Looks like the 1906 San Francisco quake had displacements up to 8.5 meters, so more than two squares. https://en.wikipedia.org/wiki/1906_San_Francisco_earthquake
