Naruto: Shippuden’s the Fourth Shinobi War arc had a few key moments that would have changed the entire narrative and plot of the anime if they had played out differently.
One such key moment is when Sakura hesitates to destroy the Rinnegan when Obito asks her to do it. This scene takes place in the Kamui dimension with Naruto and Sasuke are fighting Madara in one area and Obito explaining the history of the Rinnegan to Sakura.
It is at this time that Obito asks her to destroy the Rinnegan before it falls into Madara’s hands and he becomes unstoppable as the result of having two Rinnegans at his disposal.
Sakura, unfortunately, comes up short at this critical juncture and hesitates to destroy the eyes even after Obito asks her to. The seconds she spends hesitating provide Madara with enough time to catch up to them, allowing him to ultimately claim the Rinnegan for himself.
A major segment of the community cannot help but be curious as to why Sakura hesitated, considering that Kaguya Otsutsuki would not have been resurrected had she listened to Obito's request.
Exploring plausible reasons for Sakura's hesitation in destroying the Rinnegan in Naruto: Shippuden
1) Simply for the plot
One speculation amongst community members is that Sakura hesitated during the scene because it was something that the Mangaka, Masashi Kishimoto, desired for her. Sakura needed to hesitate for the sake of the plot so that the final battle between Naruto, Sasuke, and Kaguya could take place.
It’s one of the reasons why the Hidden Leaf village did not attempt to destroy the eye, even though they knew the risks that it would bring. Minato, Kakashi and Gaara never tried to purge it either, for the very same reason. Many feel that was crucial for the plot that nobody ever got around to destroying the Rinnegan.
Additionally, if Sakura did stab Obito in the eye, Madara would have gone after Sasuke who had the last remaining Rinnegan. Hence, this would have completely changed the plot and the outcome of the show.
2) Sakura might have softened up to Obito
Another fan theory that has been circulating over the years is that Sakura might have warmed up to Obito a little and sympathised with his plight when he was explaining the history of the Rinnegan to her in the Kamui dimension.
Perhaps this conversation, along with Obito finally realizing the grave sin of his actions, made it considerably difficult for Sakura to mercilessly put a hole through his eye in Naruto.
3) The anime was not an authentic representation of the manga
One of the more credible theories is that Kishimoto never really intended for Sakura to hesitate. Fans feel that the anime was not an authentic representation of manga, at least when it comes to this particular scene.
In the manga, the entire scenario was played out in just a few panels, with Madara entering the Kamui dimension as soon as Obito asks Sakura to destroy the Rinnegan. Hence, Sakura was not exactly given the time to hesitate in the manga, unlike the depiction in the anime.
4) Going against her ethics as a medical ninja
Another theory is that Sakura’s innate sense of morality ever since she took up the role of a medical ninja for the Hidden Leaf stopped her from going through with Obito's request. Her basic regenerative abilities were tailored to saving lives and not taking them. Hence, many in the community feel that it is quite likely that stabbing Obito in the eye was against her sensibilities.
However, the community is divided when it comes to this speculation because many are also of the opinion that a shinobi with Sakura’s resolve would be unlikely to hesitate about destroying the eye that would determine the future of the Naruto universe.
5) Human weakness
The final speculation deals with her characterization, and how Kishimoto might have used the scene as a representation of human weakness, that is if her hesitation in the anime was indeed canon. What she lacks in power, however, she makes up for in skill. This is also something that Kakashi pointed out many times. By making her hesitant, the anime was working towards making her character come off as someone who is compassionate.