An important thing when it comes to Naruto is reoccurring themes which is the difference between natural talent and hard work. The theme is evident in Naruto and Sasuke as it resonates throughout the series. It shows how innate ability is not as valuable as showing willpower and effort.
Towards the end of Naruto’s Fourth Shinobi World War arc, the tailed fox demon inside of him, Kurama is a reference to an ancient shinobi. Its name is Hagoromo who prophesized that there would be a ninja to unite the world. Naruto’s subconscious is then extracted from him and is greeted by the first shinobi. This is where it is revealed that Hagoromo reveals the true reason that Naruto and Sasuke were destined to become rivals.
As per him, he and his mother Kaguya were beings from another world who came to Earth. Hagoromo had noble intentions but Kaguya was evil and only viewed Earth as a resource to be used. He fathered twin sons realizing he cannot achieve world peace in one lifetime.
His sons Indra was of natural aptitude for Ninjutsu while Asura needed to work hard to reach his potential. Hagoromo chose Asura to succeed him and this led to war as Indra was disappointed for not being chosen. This is all relevant because Naruto is the descendant and reincarnation of Asura and the same is true for Sasuke and Indra.
This does damage Naruto’s core themes through Sasuke’s relationship with Naruto is controversial. But their equation is at the heart of the series. This is the reason they connect and clash with each other as their different backgrounds led to the same problems. Naruto had to put the work to become powerful but the outcome was predetermined way back.
The major themes being disregarded is a disappointment as the series is nearing its conclusion. Naruto and Sasuke being incarnations of two brothers do not deepen their relationship or advance it in any way. It all makes the series’ timeline very convoluted while cheapening the core relationship and theme.