Why do some earthquakes cause more damage than others?

Because earthquakes have different magnitudes. it depends on how the earthquake happens. the magnitudes measured by richter scale usually.

Why Some Earthquakes Are More Destructive ... If your heart beats rapidly during an earthquake, it still doesn't compete with high-frequency waves generated by the quake. These waves shake the ground faster than your ticker's thrumming and cause the most damage to smaller structures, such as houses.