@inthehands @ian The Korean writing system was also created all at once, although it was a decision to switch from Chinese characters to a native system. https://en.m.wikipedia.org/wiki/Origin_of_Hangul
It was “created” by King Sejong the Great, but I am somewhat skeptical that he did so truly alone—it’s easy for the boss to take credit for the team’s work, as it were. (I’m not trying to imply anything about Cherokee here, Sequoyah probably didn’t have a court of professional scholars on hand.)