Earlier quoted context omitted.
There is absolutely no evidence here that they have dunning krugers. In fact, their continued employment at a company that routinely cuts the lower performers is probably evidence against them having dunning krugers.
The guy's entire 2794 word anonymous rant is 100% about himself. If he wasn't a narcissist, he'd have managed to fit at least a few words about how a coworker was mistreated.
Not writing stories about your co-workers qualifies you for NPD now? Why are you splitting hairs?