[sweuder]

Literally in the article as soon as Myers-Briggs was brought up:

"Personality tests are full of broad generalities that should be taken with a grain of salt. Instead, personality tests should be treated as tools for self-reflection. They are indicators of tendencies, not hard and fast rules."

Just a thing to help you think about yourself, not a diagnosis.

Extraversion/Introversion is pretty deeply embedded in psychological theory, even if its not easily measured directly. FWIW