There's lots of good explanations for why Naruto is "looser" and Itachi is better than him. But why is that, is that coz u feel supperior about naruto beign outcast and u aren't? I think Narutos true strenght lies in him as he's being himself sometimes stupid but still he's improving himself in way others can't. Is it so wrong that oucast ppl can be main character. That's totally wrong way to think. One thing that I know about naruto and real life being born in to good family doesn't make u strong. As u fight whole ur life to achieve something makes u even stronger than anyone else can be though.. Naruto has Kuyubi inside him so what. Thats not his true strenght.

-Naruto does know the pain of others better than them.
-His determination to improve in his skills is something beoynd others.
-He'll never gives up if it would take his life.
-He's scared who wouldn't be.
-True strenght comes from your spirit and that's what Naruto knows well.
-Though Naruto was social outcast that's what made him as he is now.

That's only what I think and I don't want to argue about this.
Still I think strongest char is Naruto I don't measure brain or strenght, that's matter of spirit.