Remember that Minecraft is a very different sort of game than No Man's Sky. Minecraft is a completely destructable/constructable world. You can demolish the entire world down to the bedrock and build whatever you want in addition to or in replacement of what existed previously. That's why some sort of segmentation system is necessary, there needs to be some sort of unit of interactability/construction/destruction, and for Minecraft that unit is a 1m block. No Man's Sky isn't like that, it's not filled with world's you change, just world's you visit and explore. Because you don't need that fundamental unit of interactability you can use more traditional world modeling that looks more like what we've come to expect 3D worlds to look like.