Tyler Jackson was six feet tall and 150 lbs at 15, and playing really well for a freshman against older players.
His early high ranking extrapolated additional physical growth and development that normally comes with experience.
Unfortunately, he looks exactly the same now as he did as a freshman, both physically and in basketball skills. Many other guys did have the growth spurt and development in their game. So he got passed by a lot of players in the rankings.
I still think he would be a take, but he might still think of himself as the headliner of a top recruiting class. He isn't that guy, so coaches may not want that dichotomy of attitude and talent (not to mention NIL requests).
Red and co, for whatever reason, have apparently gone a different way.