"you are probably not Frida Kahlo" is not the same as "you will never be Frida Kahlo."
It's just a fact that most people are not one of the very best in their field: 50% of people can't be in the top 1%. That's not to say people shouldn't try - after all, many of the "very best" tried very hard to get where they are.
Why are you assuming that everyone has the same metric for being the "top"? There are millions of artists out there, creating from the world around them something unique to their time and place. Your base assumption appears to be that a bell curve can be applied to human creativity. Ask yourself who told you this and why.
It's just a fact that most people are not one of the very best in their field: 50% of people can't be in the top 1%. That's not to say people shouldn't try - after all, many of the "very best" tried very hard to get where they are.