The reason people (talking primarily about myself here…) over-complicate things is fear and their coping mechanisms to fear. Engineers like me enjoy making and solving puzzles. So when there is a task requiring social courage (such as publicly revealing a massive knowledge gap in order to ask a clear simple question), it is tempting to puzzlecraft the way around the simple hard task.
The leadership solution to overcomplication is not to say “you’re overcomplicating things” but to be a steadfast curious collaborator with them to encourage the person to see more clearly the challenge that they’ve obscured with needless puzzle-making. Easier said than done.