pyxi

Sasuke using the Susano for Sakura: fanart

Sasuke using his susano to protect karin and Naruto: canon

Honestly, characters like Madara and Sasuke (also Nagato, Konan, Neji etc.) teach a lot more about "never giving up" than Naruto Uzumaki.

These characters at some point in their lives lost everything they ever had, lost all hope, but still kept going, trying to change the world for better, still fought like madmen for their rightful place in the world. Maybe they used wrong methods, maybe they weren't 100 percent right, but they still kept going.

They kept trying to climb their way out of their own grave, a grave other people dig for them.

If that's not about never giving up, then what is...?