The point of the Chunnin exams is to showcase ninja from the 5 Nations and bring in money/international relations. The only ninja to get made Chunnin wasn't the one with insane physical power or traditional 'earned ability'-
it was Shikamaru. Somebody who was promoted because he understood what matters in the real world of Shinobi outside of the stadium.
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Clearly that represents what the exams are about and what standards the ninja world are looking for.
Also...Boruto
wasn't a well developed ninja? He had mastered many jutsu and chakra natures. Naruto had one jutsu and was much MUCH less mature and experienced.