Why is there so much of the earths surface at or near sea-level?

According to the hypsometric curve (plot between elevation and % of earth's surface), only about
29% of Earth's surface is above the mean sea level, rest 71% has an elevation less than mean sea
level. There are a number of reasons for this observation. Erosion of land mass by water, wind
and other forces reduces the elevation of continental features. The...

href="https://serc.carleton.edu/mathyouneed/hypsometric/index.html">https://serc.carleton.edu/mathyouneed/hypsometric/index.html