Tite Kubo's hit manga series Bleach, launching in 2001 in Japan, soon became one of Shonen Jump's "big three" alongside friendly rivals Naruto and One Piece. Fans often see these three series as the spiritual successors of Akira Toriyama's Dragon Ball franchise. However, the three shonen protagonists are not quite equal.
All good stories require a distinct and impactful lead character, and while Ichigo Kurosaki is designed to be a hero for the everyday people, this design couldn't sustain itself as well as the ambitious narratives for Naruto Uzumaki and Monkey D. Luffy. At his core, Ichigo is a hero who doesn't want anything to change, and that doesn't make for a good story. He would never become Hokage or Pirate King, meaning he got left behind in the dust.
Ichigo's characterization is the heart of Bleach, and at first, he was the story's greatest asset. He wasn't born with a grand destiny or special power on hand; he was simply a punk high schooler with a good heart and formidable street fighting skills, making him the Yusuke Urameshi of the early 2000s. Ichigo was thus a relatable shonen hero who learned Bleach's combat system as he went, training with Rukia Kuchiki and Kisuke Urahara to hone his newly-realized powers after obtaining them from Rukia.
A man of two lives, Ichigo tried to live as an ordinary student while also slaying Hollows and traveling to exotic worlds. Past a certain point though, the appeal of this story can wear off -- especially with nothing substantial to replace it. Ichigo's character simply ran out of gas.
After he obtained incredible abilities later in Bleach and became a true powerhouse, the "I'm just a kid who got powers" appeal began to ring hollow -- especially after the revelation that he was a lost son of the Quincy king, Yhwach. Ichigo resisted his Quincy heritage, also fighting and defeating the traitorous Captain Sosuke Aizen to protect Karakura Town and the entire world by extension. Then there were plots involving Ichigo rescuing Rukia from the Soul Society and rescuing Orihime from Hueco Mundo, risking his life to protect the people dearest to him.
While his actions are noble, these stories almost never advance Ichigo's character at all. He fights hard to put things back to normal and prevent villains from making drastic changes in the world. In the end, Ichigo ends up back where he started, making Bleach's story ultimately feel circular and empty. Fans can cheer on Ichigo for defending his friends, but he has no long-term goal to aspire to.
Ichigo's early characterization was effective for Bleach's initial arcs and could have laid the foundation for something more later on, such as noble goals and aspirations or a quest to change the world. This never happened though, and Ichigo's goals became too defensive and conservative for the story to evolve through him. He fought hard to save his friends and protect the world many times, but his character never moved beyond that. This contrasts poorly with other shonen leads.
Naruto Uzumaki grew up alone and feared, prompting him to dream of becoming a great Hokage to protect his village and gain recognition, even pursuing world peace as Jiraiya once did. That's something fans can continually cheer him on for. Luffy aspires to find the One Piece treasure (eventually) and become the King of Pirates. Even Son Goku had more appreciable goals than Ichigo, eagerly desiring to find and fight the universe's strongest warriors and get stronger himself. It's rather straightforward but still constructive, and Goku seeks to better himself because he enjoys it (among other reasons).
Ichigo lacked all of this, and his intentions were too defensive to move the story. So while everything else moved instead, Ichigo kept tackling threats and problems as they came like a game of whack-a-mole. He simply gained the strength needed, declared "mission accomplished," and then went nowhere. It grew tedious after a while, one reason why Bleach felt so circular. Ichigo never put any "I have a dream!" soul into it, thus Bleach and its protagonist began to slowly but surely lag behind the shonen competition.
