Charlie even said that many of the athletes who came to him were incredible talents. See Mark McKoy and Desai Williams. Maybe you haven’t read Speed Trap. He didn’t just get Joe Blows. It goes without saying, there was 1 Ben Johnson. A lot of great guys trained with Charlie, but how many went under 10, let alone 9.8 (let alone 9.7, 9.6). That isn’t a knock on Charlie, but shows that talent is huge. You can have one of the best coaches alive, get massage 3x a day for a number of years, work your ass off for years, and do all of the other things needed for success and still never break 10 (let alone run 9.58 or 19.19) if you don’t have the talent.
Bolt ran sub 20 before he was training seriously and before he was with Mills. How many people (as in, the entire world population) are capable of sub 24 without extensive training? As a percentage… not a whole lot.