Not sure if the Dunning-Kruger effect can be applied to everything (such as: humour, grammar, etc., as listed in the article), but I think pretty much everyone who has played any kind of video game (Dota, LoL, Star Craft, CS:GO, etc.) in a competitive "try-hard" environment for long enough will assure you that the Dunning-Krueger effect is indeed real.

"It's not my fault for losing this; I am clearly better than the team/oponents if it weren't for bad teammates/cheese tactics/meta abuse/lags/etc" is a mindset a lot of players have even if all evidence points to the contrary (~50% winrate in average in matches with players of similar ranking etc.).

In fact, I struggled quite some time with this myself - acknowledging and understanding one's own shittiness is one of the very first steps of actual improvement, and that's usually easier said than done, at least for me personally.