Seen it time after time over a 50 year working career. High IQ succeeds despite lack of formal education, low IQ fails no matter where they went to school, for how long, what degrees they acquired, or who boosted their careers. AOC is a prime example of the latter.
The other great truth is that the low IQ people do not recognize that they are low IQ, while both the medium and high IQ ones do recognize this.
This effect is why affirmative action, or calls for "equity" are so poisonous. An organization becomes top heavy with low-performance people.