When companies have multiple employees, in the course of work every employee has a chance to observe "gaps" (i.e. the missing pieces) in knowledge and skills in not just himself or herself, but also in other people, teams, departments.
Even when a gap is identified, not every employee is sufficiently motivated to start learning or to try acquiring skills to fill that gap. And if the gap is identified in another person or team, hardly anyone wants to "bell that cat" by publicly pointing it out!