You are stupid. First of all I don't know why nagato is even mentioned in this. who cares about him? he was just some Melancholy creep he never really had a life anyway.
Sasuke past is way worse. First of all everyone loved his brother more. Even at the age of six he felt that he had to get stronger than his brother because he felt inferior to him. He admired his brother though. His older brother not only killed his parents but his whole clan and family. He had to endure all that so thats probably why he wasn't the happy social type like naruto was. Even though people loved sasuke the only think sasuke could think about is revenge and being stronger than his brother.
Also orchimaru chose sasuke and gave him the curse mark so don't try to act like it's all sasuke fault.
naruto had it the easiest. Then garra and then sasuke