Thankfully it’s usually quite easy to dispel this myth by saying “then why are you bad at maths”. We all had the same number of hours in maths class as kids, but some had to practice WAY MORE to achieve a passable grade.
Most people can’t be Mozart. Some dedicate their lives to music, and do not get a fraction of the way there.
“Talent doesn’t exist” is a lie we tell ourselves as a society because our individualist culture sells us a pipe dream of personal greatness that many/most people literally aren’t equipped to achieve no matter how hard they try (and we should try regardless).