Of course there is, but that is pretty much the point, that Jurph and nocturnal_tick were also trying to make. The Earth’s shape is unique–“geoid” is not a description of it, as “oval” or “sphere” or “oblate spheroid” are.
And the topographic variation of the geoid is only a couple hundred meters, an order of magnitude less than the actual “surface”.
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It appears to be the former. Makes sense when you think about it. It seems geocentric, but the Earth’s orbit just happens to align with the general position of the Sun’s own angular momentum.
I went back to Ice Wolf’s link, which says that “The only way to get all the mass as close to planet’s center of gravity as possible is to form a sphere. The technical name for this process is ‘isostatic adjustment.’”
I would have said just the opposite. Isostasy is what allows us to have topography–deviations from the spherical–the mountains are compensated by lower density roots, kinda like icebergs floating in water.