I can't take Naruto seriously sometimes because I have to laugh at some of the "omg this kid must be a genius" moments of the manga.
Most of the time it's so painfully clear those are just kids. Confused, desperate, traumatized to no end, scared. Kids that want to believe in a greater good to justify the violence they commit. Kids, just kids. They don't know who to trust, they get manipulated, they make me want to tear apart the adults in their lives and scream and cry an—
Shisui's solution to stop the Uchiha coup was to brainwash Fugaku and to be honest? Fugaku was not even half the problem. The problem was that the Uchiha prejudice had reached unparalleled levels, that the system was stepping on them and had been stepping on them since Hashirama was still alive. There's no way that the clan would have stayed quiet, even if Fugaku ordered them to not follow the plan.
Shisui was smart for his age but he was desperate and he was scared and he was, at the end of the day, just a teenager. That's why he got killed by Danzo. That's why he suicided and left the burden to Itachi to carry.
Itachi was a kid too. Fuck the genius title, it is complete bullshit in Naruto. He thought that the solution was to follow Hiruzen's plan because he was so traumatized by war, he would do literally anything to avoid it. But massacring his whole clan was any better? Didn't he kill innocent people all the same? Didn't he prolong the suffering of Konoha? Hiruzen had the audacity to say that Itachi was wise as a kage in his young age, which is stupid and shows what Hiruzen thinks a kage is and how they should think.
Shisui and Itachi were not geniuses. They were kids / teenagers who happened to be more ways to mold and turn into weapons. That they were smart doesn't mean they were adults.
Neji? He was strong, he was smart and mature. He was one of the best members of the Hyuga clan at 12 years old, a pattern shared with Shisui and Itachi. However, the Chuning Exams made it very clear that Neji was as lost and confused and hollow as the rest of those "geniuses". He was lied to. It's a tradition at this point: how much info do you think they are keeping away from you so that you behave like they want you to behave?
Kakashi? He said it himself that he was stupid for believing he was such a big deal, when in fact his attitude didn't help him save his teammates or properly train his students. The genius title only served to cause him pain. In the Naruto universe, people assume you are immune to emotions or being your age if you're a genius, it seems.
"This kid is a genius" and then the story proceeds to show them making a terrible decision that is not even theirs, it's the system playing with them.
Over and over and over again.