There are a few benefits to asking questions.

1. First, being an effective leader means you surround yourself with people who know more than you do. If you have people who are closer to the work, there is a high chance they have information to share that you may not have preview to! Asking questions and listening are very effective skills for a leader.
2. Asking questions is also beneficial because while the person is answering, they might get other ideas. While listening to what they say, you might get inspired to ask more questions and lead them to more ideas that otherwise they wouldn't get to.
3. By asking questions, you educate others around you who might not feel comfortable asking questions for fear of ruining their reputation (sad truth!).
4. By asking questions, you create a safe environment where people know it is ok not to know everything and it is ok to seek help when needed.