They recruit very good players and don't shy away from recruiting guys that are likely to get drafted before they see a college field. So, they have to recruit a lot of players to account for those they will lose to the draft.
They had the #1 recruiting class for 2017 and 14 of those players were drafted. They also had six drafted from their team and three freshmen All-Americans. So, not only do they recruit very good young players but they aren't afraid to play them right away. Your player just has to be that good.
And, as with any decent college program, the wave of new challengers will come in every year.