If we only consider the terrestrial planets and moons, do you think the amount of water on earth is in the top 10%? Or are we perhaps average here? Could it be that the norm for terrestrial planets is to be completely covered with water? And that the earth is rare in its lack of water? (perhaps contrary to the normal rare earth hypothesis). I mean, we only have to go to Jupiter's Europa to find a place with a 100% water surface (although it is frozen). Do you know if any astronomer has tried to predict the prevalence of waterworlds based on available exoplanetary evidence? If perhaps it is rare for terrestrial planets to have continents we can understand why intelligent life is not all over the place in our neighborhood. It's hard to built fancy technologies if you're swimming, no matter how smart you are.