I think it's really about the appropriate scale and density. It doesn't matter if there's only 4 or 5 distinct areas of you only need to visit those 4 or 5 to have a complete experience. That's really what minecraft got right. You have a fun game even if you never leave the first biome. You don't have to necessarily move around enough that you get bored.

NMS, otoh forces you to go from planet to nearly identical planet.