That isn't what that shows, and the article you linked to even warns:

> In popular culture, the Dunning–Kruger effect is sometimes misunderstood as claiming that people with low intelligence are generally overconfident, instead of denoting specific overconfidence of people unskilled at particular areas.

Dunning-Kruger has also been discredited with suggestion they may have been over confident themselves:

The Dunning-Kruger Effect Is Probably Not Real (2020) https://www.mcgill.ca/oss/article/critical-thinking/dunning-...

Debunking the Dunning‑Kruger effect – the least skilled people know how much they don’t know, but everyone thinks they are better than average (2023) https://theconversation.com/debunking-the-dunning-kruger-eff... the Dunning‑Kruger effect – the least skilled people know how much they don’t know, but everyone thinks they are better than average