About all it omits is that people at the bottom of the scale generally didn't even understand the questions they were asked, so their answers were really all over the place.
But the key takeaway -- the D-K effect is about you, much of the time, even if you are expert about some things -- is usually neglected. D-K is about everyone: The more certain you are, the less likely it is you have reason to be.
However outside of your specific area(s) of expertise your confidence in your ability is likely to far exceed your actual ability (on average).
So experts are still susceptible to DK effect for areas that lie outside their expertise. Even (or perhaps especially) if they think their expertise gives them special insight into another field.
For example, I read a lot about modern physics but am not a physicist. I would give myself an above average understanding but would likely fail an exam.
Time and again the symptoms of the problem I'm troubleshooting have correlated with some prior experience, triggering a prediction, which has been wrong.
And I've actually passed multiple cloud certifications, too.
IT is just complicated.
Would be interesting to find out how wrong I actually here...
However, if you haven't had the service blow up in your face a few times, you'd better have a photographic memory to pass those certs.
It's as much about you and the things you are an expert about as anything else; D-K isn't just a low-ability effect.
Reversion to the mean would be underperforming past elite performance, not underestimating actual performance.
And it would draw toward the mean, not the ~70th percentile.