The cells and worldspaces are needed for a engine that allows huge amounts of persistent dynamic objects that can be removed from and added to the world freely., That is the reason why we don’t see games with large worlds like this in other engines. Even more so when the game has to run on consoles too. Neither No Man’s Sky, nor Outer Worlds or Cyberpunk have worlds or places full of persistent dynamic objects, nearly everything is static and hard baked into the world.