It's pretty obvious that practice isn't enough. There are so many examples all around us.

If someone is born with down syndrome, they are extremely unlikely to graduate from university. If someone's eyesight isn't perfect, they will probably never become a commercial pilot. If you're autistic, you probably won't become a professional negotiator...

There are so many cases, sometimes rooted in tiny genetic differences which can make a huge difference when it comes to winning and losing...

And when you take luck into account; you could argue that even the most genetically fit human for a specific field is unlikely to become the best in that field even if they practice non-stop. There is so much luck involved, a single tiny problem can ruin an entire career before it even starts.