In Naruto, ninja techniques (Jutsu) refer to a specialized skill set that only ninjas can utilize. There are three fundamental types of techniques: Ninjutsu, Genjutsu, and Taijutsu.

However, throughout the story, we primarily see the main character, Naruto, mastering Ninjutsu and Taijutsu. But why is it that we never see him utilizing Genjutsu?
There are two reasons for this!
The first reason is that Naruto is a combat-focused ninja. In battles, he often engages directly with his opponents.
The second reason is that even towards the end of the Naruto series, he still struggles to control chakra effectively. Genjutsu, on the other hand, requires a high level of chakra control and intelligence. Specifically, advanced Genjutsu often involves intricate techniques that, if executed inaccurately, can have no effect. Even Jiraiya faced significant challenges when attempting to perform these techniques.
For Naruto, the main issue is that he cannot adequately control his chakra due to the presence of Kurama’s chakra within him. He only learned how to manage his chakra in a primitive way after he began to utilize Kurama’s chakra. By the time Naruto became proficient in controlling his own chakra, there was no master of Genjutsu available to teach him how to use those techniques.

Additionally, during the Fourth Great Ninja War, Naruto wouldn’t have had the time to learn any Genjutsu techniques in such a short period.
By the end of the story, Genjutsu also becomes less significant due to the presence of powerful foes (Madara and Obito), who possess the ability to control chakra to such an extent that they cannot be affected by Genjutsu.
With all these factors in mind, it’s entirely understandable why Naruto never learns to use Genjutsu in Naruto Shippuden.