I just included that to point out that there is a tangible difference at the high end, it’s not just “everyone getting 800 on the math SAT is similar in their mathematical ability”. Whether competition performance correlates to mathematical achievement in college later in life is unclear, although I do want to point out that many do end up becoming professors and such. Many of the rest don’t show up on the “math radar” because they major in computer science instead and get jobs in the industry.