This is the issue with every young adult novel or comic or movie. The worlds in any young adult series are basically only possible when all of the adults are functionally retarded or insane.
These shows and movies are written for a teenage audience so the adult characters are barely there. The parents are absentee and do not exist. Naruto has a city crushing demon inside of him but has no supervision whatsoever and raises himself despite the immense danger. Erin's father turns him into a Titan. Harry Potter's parents hide him in the worst possible place, in a broom closet, rather than have a powerful wizard family watch him or have him grow up at the wizard school. The parents in the Hunger Games do not even fight in the revolution when it happens and just let their kids wage worldwide hunger games level conflict. Because the stories are all about putting kids front and center no matter how stupid the plot ends up being.
It sort of makes sense in Battle Royale or Hunger Games because the premise is that young kids are forced to kill each other to control society. But when the average age of the ninjas or scouts in Naruto or AoT are 14 it stretches credulity. AoT went in the extreme and had kindergarten child soldiers infiltrate the walls which was hilarious in retrospect. Like a bunch of five-year-olds graduated Navy Seal training and understood the politics and nuances of being a spy.