That hard work is what matters in life, and you make your own destiny.
Naruto: Actually the son of the previous Kage and the Jinchuriki, direct descendant of Ashura.
Rock Lee: Gets fuck all to do.
Neji: Dies in a pathetic manner, never escaping his fate.
This all boils down to real world 'Fate' exists or not. If it's pre decided than why bother trying and if it's not, then work hard to achieve anything.
But if a Baby learns to walk which is pre~determined, bound to happen, that's fate. But how he utlises it is upto him, if he keeps walking he will bump on some wall or some shit. But if he stops, that's his own will.
You can't deny the fact naruto worked hard and even harder later on.
When they were all chunin, Naruto wasn't even at the top, no destiny kicked in for him.
Hell Neji and Shikamaru were the ones to become Jonin first solely on merit and Hardwork.
Naruto only advantage back then was him being an Uzumaki, which helped him immesnly with Shadow clone because that requires a lot of life force and Uzumaki are known to have it.
But to hell everyone had their own advantages, Shika trio were all Kekkei genkei or some special jutsu user. Neji, Hinata and Sasuke had Sharingan and Byakugan. Shinzo was the collest guy around. Rocklee clowned a fuckin Jinchuriki and the list goes on. They all looked more impressive every now and then.
Coming to shippuden, all them choose to guy normal route after that.
- They all had access to learn from the best, they all had access to learning Senjutsu, they simply choose not to. Which was Sasuke and Naruto advantage which they gained themselves.
Post that, Naruto was training with two jonin to master a single jutsu. Sasuke was learning with Orochimaru. Both choose their path and worked on it again.
Then comes the sage jutsu and Sasuke getting Mangekyou, these powers have more downsides than plus sides. Too much of a risk, going blind vs turning into a stone, these are forbidden level jutsu we are talking about.
Yet they risked it, other didn't.
Someone like Conan managed to push obito to use Izanagi/Izanami. That should be enough to tell if one works hard enough they can topple such people.
Tsuchikage who got clowned by Madara in his young years, ended up learning Kekkei Tota.
Again it's all just hardwork at the end of the day. Some start with a huge advantage at hand and some don't.