I'm not seeing the imposter side of things personally but maybe he does come across like the old addage : dumb people think they know everything, smart people know they know nothing. Or something to that effect.
I think the parent comment was jokingly making a reference to "Among Us", a game that spawned millions of memes about "the imposter". But my assumption could be wrong.
Almost everyone is under (the folk version of) the Dunning-Kruger effect about the Dunning-Kruger effect.
Since you linked Wikipedia, I'll quote it.
> Nevertheless, low performers' self-assessment is lower than that of high performers.
> Among laypeople, the Dunning–Kruger effect is often misunderstood as the claim that people with low intelligence are more confident in their knowledge and skills than people with high intelligence.
