Research shows that sexual frequency, in both short-term and LTR's, is determined by extraversion for both genders.

Extraverted men have a higher need for stimulation, they pursue sex more, and are more open to a variety of sex behaviors. "Chad", therefore, is simply a label for "extraverted guy".

Because reddit attracts introverts, we're only hearing from the men who are inherently less successful by nature of their personality.