Your latest information is not a clear image of H2O economy of the evolving earth.
it takes a lot of hot and cold and solar wind to dry a planet into a rock, a solar system planet's natural state is to have a lot of ices, if it wasn't for atmospheric loss.
You can see that there are vast amounts of H and O inside the sun and solar system, and the earth would have constantly received large volumes of water throughout it's formation.
Solar radiation and freezing conditions evaporate/sublimate water and volatile gaseous chemistries, so inner planets would have more water if it were not for solar radiation and dry frost, because it sends the masses of water back out into space. H and O bond well with other minerals and they exist in many acids and minerals more prevalently than in water, i.e. there is more water 100ds of kilometers inside the planet than in the oceans.
Hydrogen and Oxygen are some of the lightest elements and most likely to escape to the high atmosphere, so the end balance of the planets has been an equation between massive constant arrival of water and massive constant evaporation, where only the earth has had ambient temperature, high planet gravity, and the magnetic field to keep water as oceans, rather than H in ices and acids.
The atmospheric losses can be more of light Hydrogen than Oxygen, Venus has masses of atmospheric oxygen and almost no hydrogen.