But it's not genetic or physical or talent. It's because most of us don't have the discipline or mentality to be the best. We fuck about in 2fort instead of playing dm, watching our demos and thinking about how to improve.
Some of it comes down to intelligence. Stupid people won't make as good as a decisions as smart people, but also having the discipline to stick to a good training regime is crucial.
Basically, hours do matter, but mostly if you apply them in ways that will yield the most improvement.
A football analogy. When Isco signed for Real Madrid, he wanted to impress so he turned up an hour early for training on his first day. When he got there, Cristiano Ronaldo was already out on the training field practicing. Ronaldo isn't the (second) best player by coincidence luck or even just talent; he's worked hard and trained in the best ways to improve.