It's a weird coincidence that we not only have water on earth (hypothesized to have been delivered by many comet impacts), but also not so much that the surface would be completely covered deeply.
It's hypothesized that it was in shallow tide pools, on the border between water and land, that life first evolved. To have shallowness seems to have required fantastic luck. Additionally, tides, if they were necessary, required a massive moon.
This possibly explains the Fermi paradox. Someday we may explore many star systems, consistently finding no life because of either too much water or too little.
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