I haven't read the article, but I've listened to a podcast featuring the author. He voiced that determining the "chaos" of the field or game is very relevant to

I haven't read the article, but I've listened to a podcast featuring the author. He voiced that determining the "chaos" of the field or game is very relevant to whether someone should focus on specialization or be a generalist. For instance, chess has more defined moves and outcomes, making it better to specialize in chess early if you want to be good, whereas poker players can benefit from learning across multiple domains. David Epstein also acknowledges natural skill is important. Perhaps Federer would have been great regardless, or even better as you say. Perhaps he would have burned out too.