Jesus is King. Although he came as a servant, He is now King. God the Father, the Son and Holy Spirit are one triune God. To ask God to do all the work himself is like asking the King to mow the lawn. A king has servants and God has a host of heavenly beings.
Angels wait and listen for the voice. God’s words come out of our mouth. Angels agree with God’s words and take action.
Various persons in the Bible did not consider it was an angel visiting until later. Peter was released from prison by an angel. The angels who visited
Angel visits were through out the Old and New Testament. Angels shut the lion’s mouths and preserved Daniel.