incompetence
n.a lack of the skills or knowledge needed to do a job well. You use this to describe when someone fails because they are not good at what they do.
n.the inability to perform a task or job to a required standard due to a lack of skill, knowledge, or ability. Frequently used in professional or administrative contexts to describe systemic or individual failure.
“The manager was fired for total incompetence.”
“The project failed not because of a lack of funding, but because of the sheer incompetence of the leadership team.”
“While minor errors are expected in any large organization, the systemic incompetence displayed during the crisis suggested a fundamental breakdown in the company's training protocols.”
Often paired with the preposition 'of' or 'in' ('incompetence in his duties').
From French incompétence, equivalent to in- + competence.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.