He is just a boring normal person, not Shonen material.
No unrealistic goal, no hardworking beyond limits, no smile at hard time moments, no I want to befriend my enemies despite they killed half of earth.
He is just a normal guy, accidentally was introduced to community of sorcerers, and went along with it. Now has friends he wants to protect.
Yuji was a mad science experiment by birth, allowed to live a normal life in obscurity most likely on purpose to keep his existence hidden. His mom was a sorcerer with a mad strong gravity based CT, and was Kenjaku’s last host when she gave birth to Yuji!
Choso - the death womb painting, that Choso - instinctively recognized Yuji as his brother from another mother.
Oh and Yuji’s supernatural level athletic ability was noted by Fushigoro, literally in chapter 1, as being similar to “Zenin-Sempai” aka Maki, who possesses a heavenly restriction.
Tell me again how Itadori Yuji is just some normal bloke thrown into a supernatural secret society and not a typical Shonen main character.