A lot of the time, these early bloomer types end up fizzling out to nothing, if their future growth is predicted based on their current ability (when they actually don't have much further room for improvement).
Nowadays in football players hit their physical and technical peaks faster than ever, so a player being a teenager no longer automatically means they have vast room for improvement. A teenager's ability, now more than ever, is not a solid indicator of future potential.
Yamal is an example of a player who despite being 18, is already close to his peak. The difference is that his baseline ability is so high that even a small level of improvement can make him a Ballondor winner. He has likely already reached or almost reached his technical/physical peak, however, unlike other teenagers, a little improvement in his mental/tactical understanding will make him an all-time legend. But more and more football is spitting out teenagers who are already close to their peaks.
Roony was a professional with FC Copenhagen at 16 and was touted to be one of the best talents in football. But at 20 he doesn't look much different to what he was at 16, granted that he missed a year due to injury. And he is probably an excellent example of this. His physical build hasn't changed from 16 and even at that age he looked old af in the face. Not withstanding some age inaccuracy, he could have passed for 25 when he was 16.
In such players as mentioned the main room for growth they will have is mental/tactical because they probably have achieved their technical and physical peaks already. And he doesn't seem like a super intelligent player. I think he is just another of the breakout teenagers who developed very fast compared to their peers but doesn't have much further to go nowadays.