Masashi Kishimoto definitely created an unparalleled Shonen anime/manga with Naruto. However, in order to make Naruto, Sasuke, and other characters shine, some important and powerful characters were nerfed along the way. The biggest victim of them all was probably Hiruzen.
Sarutobi Hiruzen is the Third Hokage, who was hailed as a God of Shinobi. During his lifetime, he had become the most powerful Kage and was also considered the strongest Hokage in history. But all that is before the main characters were promoted to the post of demigods.
Masashi Kishimoto failed to flesh out Hiruzen in Naruto
Hiruzen has a huge tag of the Third Hokage attached to his name and is considered one of the most powerful characters in the beginning of Naruto. But as the series continued, fans noticed that he was slowly being replaced by other characters. While this is natural since the protagonists are bound to be the strongest, it becomes an issue when suddenly the once OP Kage becomes a nobody.
The only information that fans have about Hiruzen’s capabilities is from second-hand details from other characters in Naruto. The series itself does not show the character using many special techniques. Fans are left to believe their ears, with little to no information on exactly how he defeated his enemies.
Now, one might argue that Hiruzen was powerful during his prime. But Masashi Kishimoto had the opportunity to show his strength when he was reanimated via Edo Tensei. Yet, he squandered it away by showing the ex-Hokage using basic jutsu, shuriken, and other powers that were easily countered.
The power-scaling in Naruto did Hiruzen no favors
Hiruzen was a powerful Kage during his time, that is, at the time when power scaling was not absolutely screwed. As the story progressed, characters became ultra-powerful and came up with earth-shattering Jutsus. Both Naruto and Sasuke became equal to demigods with their unbelievable chakra reserves and abilities.
But before them, the general measurement of strength depended on smartness, knowledge, dedication to one’s craft, and, of course, talent. Hiruzen was far more intelligent and strong than the average shinobi. In that particular setting, Hiruzen was obviously a terrifying existence.
However, in Naruto Shippuden, formidable villains appeared one after another, leading Naruto and Sasuke to achieve skills beyond the comprehension of shinobis. As they achieved the ranks of literal demigods, Hiruzen was left in the dust to become an unremarkable character who is only a legend in the history books of Konoha.
Naruto manga is available to read on Viz Media, and the anime is currently streaming on Crunchyroll.