No Man's Sky dev reflects on the new Very Positive rating on Steam and promises that this is only the beginning: 'We aren't even close to being finished yet'

In the way a sandbox should, yes - better exploration, mechs, expedition stories, freighters, better base building, etc. It's a sandbox game, it's not feasible for a game to be as deep as a rpg and wide enough to do anything you want without adhering to a story or dev-induced goal. Dwarf fortress might come the closest to that, but that's only because they have a super wide fortress mode and a super deep adventure mode and they are fully separate.

If you want a deep gameplay loop, play a game meant for it like a rpg. Those are meant to be deep but relatively narrow to keep you on the story. If you want a wide pool to do whatever you want, play a sandbox like NMS or Minecraft.