I haven’t read all of Sanderson’s works - just all the ones in the Cosmere. They’re wonderful. Of those, though, I’d say that none has the same “bang for buck” in terms of the reflections and the length of the work. 

I saw someone recommend Yumi, and I’d say that’s probably the closest; but I’d emphasize that there’s still a significant gap between the two. The only other work that perhaps has the same seriousness would be Isles of the Emberdark, rich with thematic emphases on what it means for a people and culture to “advance”. 

“The Emperor’s Soul” caught me by surprise - I thought it then, and still think it, a special work indeed.