Why is Jesus the Messiah not the son of David but a descendant of David?

Why is Jesus the Messiah not the son of David but a descendant of David? In Matthew 22:45, Mark 12:37 and Luke 20:44, Jesus warns about the teachings of the Pharisees and teachers of the law who claimed that son of David—a son of descendant of David, his own flesh and blood is the Messiah—The Anointed One. Matthew 1 is the genealogy of Joseph, who was a descendant of David and thought to be the father of Jesus. In his earthly life, Jesus is considered to be an Israelite and a descendant of David because through the Holy Spirit, He was born to Mary, who was pledged to be married to Joseph in the house of David of the tribe of Judah. Jeremiah 33:15 In those days and at that time I will cause to sprout for David a righteous Branch Isaiah 11:1 Then a shoot will spring up from the stump of Jesse, and a Branch from his roots will bear fruit. Zechariah 3:8 For behold, I am going to bring My servant, the Branch. Zechariah 6:12 the LORD of Hosts says: ‘Here is a man whose name is the Branch, and He will branch out from His place Romans 1:3 regarding his Son, who as to his earthly life was a descendant of David, Revelation 22:16 "I, Jesus, have sent My angel to testify to you these things for the churches. I am the root and the descendant of David, the bright morning star." Note: Greek to English translation of manuscript In Revelation, genos–descendant In Matthew, huios–son Use of the term 'Son of David' by people in Matt. 21:9, 15 is only a "Messianic title" in the gospel of Matthew. John 8:58 “Truly, truly, I tell you,” Jesus declared, “before Abraham was born, I am!”