Within the world of Naruto there are different ranks of ninjas, where the Genin are the lowest category ninjas with basic and simple missions, the Chunin who are of the middle category and the Jonin who are of the highest category.
That said, the Chunin Exams or Chunin Selection Exams are a series of tests to select a Genin and promote him to the Chunin rank, and although most of the main characters were promoted to this rank or beyond, there are some who have failed, so what happens to them?
Ninjas who have not advanced beyond the rank of Genin are often ridiculed and given the title of Eternal Genin, and examples include ninjas such as Kosuke Maruboshi and Mighty Duy, Might Guy’s father, which many underestimated. his skills (via CBR).
But it is worth mentioning that the rank does not always indicate the level of strength, since a Genin can possess a power much higher than the average Jonin, as demonstrated by Mighty Duy when he fought against the Seven Swordsmen of the Mist, while Kosuke is very strong but he remained Genin for other reasons.
There is no rule that prohibits a Genin from taking on higher ranking missions, and it is even possible to jump directly to a higher position, as in the case of Naruto who was never promoted beyond Genin and was directly promoted to Hokage.
So in addition to staying a Genin with all that that implies, after failing the Chunin exam a ninja can try to be a rebellious ninja with skills above the average bandit or mercenary, which would make customers pay him a good price. amount of money for your work.
There are also other broader job opportunities because the Academy offers courses that do not always focus on ninja skills, so graduates are highly desirable to employers in the everyday world, so the experience and skills of a Genin they are valuable and there are employers willing to pay big bucks for them even outside of the ninja world.