And let’s not forget all the rotating stations. There you’re on foot, moving through an environment that is rotating around a center of axis, which is in orbit of something that is in orbit of something…That is also incorrect. Players move every day in other moveable objects. ED has tons of nested grids. Except that in the case of ED, they work. For example, planets actually orbit and move around within a star system. And players walking on the surface of a planet or flying above it are doing so on a moveable object and subject to their grid, a grid that itself moves around in the star system. In the case of multiple satellites we can be talking 3, 4 or even more grids nested into each other, and then you can be in a station orbiting the last one, moving inside it. Each one with its own gravitational, coordinates and physics grids. And players transition constantly from one to another without exploding their own ship for no good reason like in SC.
These types of nested grids aren’t unique to SC or ED. Space Engineers has variable gravity on moving space ships, though it uses “No Man’s Sky” fixed worlds. Kerbal Space Program also does this kind of thing. Hellion did as well, IIRC.