I don't get why introversion is considered a more Beta Trait.

Vladimir Putin is introverted but is probably the most Alpha leader on the planet right now.

I have read historical accounts of people that knew Hitler and Napoleon before they where famous both men are described as loners or oddballs with few friends. These sources come from people that served with Hitler in WW1 and the diaries of people that attended the French military academy with Napoleon. However both Men became very good leaders and motivators both domestically and militarily, I will add that Hitler also believed a very irrational ideology but I am just focusing on leadership ability.

Maybe its a western 21st century cultural concept that Extroversion is more Alpha but the opposite could be believed in other times or cultures?

Please share your thoughts