Freedom to persue what they like and they like sports.

Speaking of tennis, you know how impossible it is to transition from clay to grass. All the greats Federer, Sampras, Agassi all can't do it. But look at Nadal and now freaking Alcaraz! Maybe it's the competition, the rise of Federer portends the rise of Nadal and the rise of Nadal portends the rise of Djokovic and now Alcaraz is rising to be the best ever. Only with strong opponent will you discover your own limit. So, it's the competition that fuels their greatness.