Throughout the series, Naruto and Sasuke's growth and development have been central to the storyline. Their dynamic as friends and rivals has been a driving force, with one often surpassing the other at different points. In the early part of the series, Sasuke appeared to have the edge over Naruto in terms of natural skill and talent.
Consideration of various plot points in the story may lead to the argument that Sasuke would not have been able to defeat him without the assistance of his Curse Mark. (Please note: This article contains spoilers for the Naruto series.)
Explaining why Naruto was stronger than Sasuke without the latter's Curse Mark before the time skip
Throughout the first part of the series, Naruto's increasing strength in comparison to Sasuke is a crucial plot development. Author Masashi Kishimoto illustrates this in various ways, demonstrating that Naruto's prowess exceeds Sasuke's without the use of the Curse Mark. This is evident during the Chunin Exams arc, when Sasuke is unable to defeat Gaara while Naruto successfully emerges victorious.
During the Tsunade arc, the main character learned the Rasengan from Jiraiya, which was said to be more powerful than the Chidori that Kakashi taught Sasuke. This became evident when Naruto's Rasengan caused more damage than Sasuke's Chidori during their confrontation at the top of the hospital, much to Sasuke's frustration.
Sasuke's need for the Curse Mark to keep up in their final battle at the Valley of the End before the time skip is evident. It is strongly arguable that he would have been defeated without it, confirming his weakness at the time.
The decline of Sasuke's character
Sasuke over the years in the series (Image via Studio Pierrot).
Many Naruto fans believe that Sasuke was a well-developed character in the first part of the series, but his portrayal declined steadily in Shippuden. Despite initially making a strong comeback and his development aligning with the story's events, Itachi's death and the revelation of his actions negatively impacted Sasuke.
Masashi Kishimoto, the author, seemed to have conflicting ideas about Sasuke, wanting to portray him as both an antagonist and an antihero. This resulted in the character's motivations wavering after Itachi's death, leading to some readers and viewers feeling disconnected from his actions.
His choice to join Team 7 in their battle against Madara (and later, Kaguya), only to betray them later, try to kill Sakura, and fight Naruto to the death, seemed forced and caused the character to suffer throughout the rest of the story.
Final thoughts
One could make the case that Sasuke, without the Curse Mark, was not as powerful as Naruto since their confrontation with Neji Hyuga in the Chunin Exams arc. Nevertheless, as they clash at the rooftop of the hospital, it becomes evident that the narrative is affirming Naruto's superiority over Sasuke.
Editor's P/S
As a passionate Naruto fan, I have always been fascinated by the complex relationship between Naruto and Sasuke. Their rivalry and friendship have been a central part of the series, and I have always been intrigued by the impact of Sasuke's Curse Mark on his strength and character development.
In the early part of the series, Sasuke appeared to have the upper hand over Naruto in terms of natural skill and talent. However, as the story progressed, it became clear that Naruto's strength was increasing at a rapid pace, and he was able to surpass Sasuke without the assistance of the Curse Mark. This was evident during the Chunin Exams arc, when Naruto successfully defeated Gaara while Sasuke was unable to do so. Additionally, during the Tsunade arc, Naruto learned the Rasengan, which was more powerful than Sasuke's Chidori, further demonstrating his growing strength.