While Caesar, the king of the Roman world, was showing everyone how great he was by counting all of his people, God the king of the universe, was showing the world how great he was by sending his Son into the world as one of his people.
David Helm, The Big Picture Story Bible (p.255)
God uses the humble things of the world to shame the proud.
Luke 3:1-2 (emphasis mine):
In the fifteenth year of the reign of Tiberius Caesar, Pontius Pilate being governor of Judea, and Herod being tetrarch of Galilee, and his brother Philip tetrarch of the region of Ituraea and Trachonitis, and Lysanias tetrarch of Abilene, during the high priesthood of Annas and Caiaphas, the word of God came to John the son of Zechariah in the wilderness.
Luke lists all of the men with worldly power, but then says that true power (God’s word) came to a nobody in the wilderness.