What does Moses’ final question, asking to send someone else, shows?

Moses runs out of excuses. Now it becomes clear that he does not want to go. His unwillingness underlays his objections. In Exodus 2:1–25 Moses had compassion with his people, he chose to be mistreated with the people of God (Hebrews 11:24–26; see exposition on Exodus 2:12). But now Moses is at ease in Midian while Israel is in distress.