The same ego that makes a high school kid think he can waltz into a Georgia/Clemson/wherever locker room and win the job from uber talented kids who are already there, is the same ego that doesn't know how to cope with the notion of being second-best.
I have the same thought as you every time I see a recruiting article about some ballyhooed recruit joining an already stacked roster. Sometimes they will win the job, like at Clemson, but more often than not you know what is going to happen. I recall an article about UGA last year-ish getting some five star recruit to join their class that already had five star recruits at the same position, and we all know damn well that someone is gong to end up leaving. Maybe the article was about this same guy, I can't remember.
Look at Nebraska's QB situation. Martinez still has multiple years remaining, and we are sitting pretty with high-ranked verbal commits for the next two classes already. That is awesome, but assuming Martinez stays healthy, I think we already know that between McCaffrey and Smothers, there is a very low likelihood that both of them will serve out their time at NU. Someone is going to end up being the heir-apparent. The other will likely transfer. Then the next hotshot high school kid is going to commit, who will either become a starter or will eventually transfer, then the next...