Not who you asked and and not anonymous. But I know introversion is not learned because I lived it. Decades of making an effort to be social enough never made me any less introverted. I assume the same is true for extroversion but I can't speak from experience there.
Maybe yours is innate. How do you know that's true for all people ? You don't.
How do you know the opposite? You don’t.
See how that works? Pipe down little buddy.
The burden of proof is on you. It's funny how personal you've taken this, lol.