Jesus Christ is the Son of God, the second Person of the Holy Trinity. He had every opportunity to become a powerful political figure (see e.g. his triumphal entry into Jerusalem after raising Lazarus from the dead, celebrated as Palm Sunday) but didn’t. So why would he write a book when he had work to do directly? At least I have answered your question of why he wouldn’t.
Jesus Christ is the Son of God, the second Person of the Holy Trinity. He had every opportunity to become a powerful political figure (see e.g. his triumphal entry into Jerusalem after raising Lazarus from the dead, celebrated as Palm Sunday) but didn’t. So why would he write a book when he had work to do directly? At least I have answered your question of why he wouldn’t.