Being good at something isnt determined at birth.
That’s not true. Savants and prodigies are people who are good at something from birth. Terence Tao was a university level mathematician at age 9. Even if you were right that you can’t be good at something inherently, genetics and birth obviously play a huge role in whatever you do. No matter how hard a 1.5m tall person works, they’ll likely never become a pro basketball player and certainly not the best
Yeah there’s a few exceptions. Emphasis on few. So few that it’s not going to have any effect on your life. Whatever field you want to excel at, you can, and it’s not going to be dominated by the very rare cases of savants. You can be a theoretical physicist smarter than Einstein.