Incompetence

noun a person who is clumsy or inept at a particular task

• The bungler's incompetence led to a series of costly mistakes in the project.
• That bungler messed up the whole job.
• Don't hire that bungler, he'll just make a mess of things.
• She was a bungler when it came to relationships, always managing to ruin them somehow.

verb gerund or present participle form of the verb 'bungle'

adjective showing lack of skill or aptitude

• The bungling of the project by the inexperienced team led to costly mistakes.
• I can't believe how bungling they were with organizing the event.
• He's such a bungling fool, always messing things up.
• Her bungling of the situation was like a comedy of errors unfolding before our eyes.

adverb In a clumsy or unskilled manner

• The new employee ineptly handled the project, causing delays.
• He ineptly tried to fix the sink but only made it worse.
• She ineptly tried to play the guitar and ended up sounding terrible.
• His speech was ineptly delivered, lacking any passion or conviction.

noun a word that refers to a person, place, thing, event, substance, or quality (effect)

• The Dunning-Kruger effect is a cognitive bias where people with low ability at a task overestimate their ability.
• You know that guy who always thinks he's the best at everything? That's the Dunning-Kruger effect in action.
• Some people just don't know what they don't know, thanks to the Dunning-Kruger effect.
• The Dunning-Kruger effect is like wearing blinders that prevent you from seeing your own incompetence.