If Jesus meant the Bible to be the Word of God (rather than himself, cf. John 1), why did he never write a single book?

There is the written word of God and then there is the Word of God. This is where capital letters are important!

The Word of God is one of Jesus' many names / titles. That was how He was known in Heaven before He created this planet and all life on it. John 1:1-14 explains how the Word was with God in the beginning, and was God, and made everything that was made. Then (in time) the Word became flesh, adding human nature to His divine nature via the virgin Mary, and then we got Jesus on Earth.

When you are the glorious Word of God, you just need to speak and you create, and you sustain what you create, for your every word is pure truth, and life, and the way to the Father. All humans have to do to get total truth, pure life, and brought home to the Father is to believe the words of Jesus. Those spoken words were heard by hundreds of believers while Jesus lived on Earth, and after He returned to Heaven, He sent the promised Holy Spirit to remind them, and to guide them into understanding and learning. See John 16:7-15 & 15:26-27 where the disciples are charged with the responsibility of testifying about Jesus. They did that both verbally and in writing (the New Testament).

The written word was never designed to supplant the living Word - Jesus! We have both, and each compliments the other! The uniting force between both is the blessed Holy Spirit who seems to be grossly disrespected in the things of God by those who think human reasoning is more important than He is. I do not refer to yourself! I refer to those who tamper with the written word of God to try to lower Jesus from His exalted position as the Word of God, who is God.

To complete the picture, Jesus came to earth to SHOW us the Father and the Word... [John 1:14]; [John 14:9].

Jesus only wrote in sand. He did not want his teachings to become dogma. Seems, though,that is exactly what happened anyway.

He didn’t write a single book because he didn’t want to be a famous author. Don’t you understand that Jesus is the most famous person in the word and the only thing he did was die on a cross and return to life after three days. Eight different people wrote about him in affidavits as witnesses to him.

Because He IS the BOOK!

Friend I don't want to seem mean here but Jesus did write a book not on writing Jesus wrote a book by making millions of people Christians that's Jesus Book and it's a continuing book that gets bigger and bigger each day as Christianity gets spread from one Christian to another.

Jesus was the Word of God not as he wrote the Bible but was God’s spokesman, because according to John 12:49,50 that whatever he spoke was what his Father commanded him to speak.

As for the Bible, everything that is written in it didn’t come about from any man’s interpretation but men were moved by Holy Spirit to write God’s thoughts according to 2 Peter 1:20, 21.

He had other things on his plate. He left that to his followers.

Jesus is the Word made flesh.

His ministry didn't last long enough to take time for him to write it down. He knew evil men were going to kill him eventually.

The Bible did not come about for a few generations after Jesus....