The same argument could be made for C.Ronaldo. Don't care what Messi has achieved at 24, Zidane was a late bloomer, but the difference in ability is obvious. In terms of talent there might not be that much of a difference between them, but in terms of vision and intelligence on the ball the difference is there for everybody to see, and that is why Zidane retired as one of the best players in the world at 34, while i'm pretty sure Messi won't be so good when he loses his pace and physical ability.