This just pushes the question back one step. How many people have the opportunity to buy a cello at a young enough age to practice enough hours to become the best?

I'm not saying it always ends in luck, actually I just don't think this is the right line of reasoning. Frank's point is about the importance of luck in the real world, but also about taking the appropriate attitude towards it. As weird as it might sound, those two points aren't necessarily related.