“because all the best football talent is in that region” this is obviously true, because the playoff teams are from somewhere other than the south.
But where do their athletes come from?
That is based off analysis by Nate Silver. The SEC has the most HS talent per-capita.
Meyer is able to supplement his base of Ohio with recruits from the South and California. His best defensive player, Joey Bosa, if from Florida. Oregon’s base is California but they bring in players from all over the nation including Texas and Florida.