I'm not interested in what he did when he was in high school. It's utterly irrelevant now. There are plenty of kids who's high school film looks awesome and they go on to do nothing in college. Look no further than Riley Burt if you want an example.
And his running ability isn't the only thing that factors in to why he wasn't getting more playing time. Maybe, like Burt, his vision isn't very good or he struggled to get the playbook down. Maybe he's not good at pass protection or he has fumble issues. There's a lot more to playing running back than just taking handoffs and running fast.
If this kid was as elite, dynamic, etc as you're making him out to be, he would have earned more playing time at FSU. Simple as that.