Why did only 4 people write about the Life of Jesus Christ? Judas died and was replaced by Matthias. There were at least eleven intimate disciples of Jesus Christ who could write the genuine life of Christ. But we have only 4 books which record the life of Christ. Moreover, only Matthew and John are of the 12 disciples of Jesus.

Is there any historical reason why the other disciples did not write the Life of Christ?

Are there any other less authentic books which record the Life of Christ?
Way more than four people wrote about the life of Christ.  Literally hundreds of 'gospels' included stories about Jesus of Nazareth—from the Gospel of Thomas to the Epistle of Barnabas to Gospel of Judas to Marcion in his own Gospel.  The only difference is that the early church either didn't trust the veracity of those 'gospels' or else they found them to be not as good as these four.

Additionally, we have external sources such as Flavius Josephus and Tacitus who record stuff about Jesus. But those are strictly 'historical' not even religious in nature.

As such, the early church said that the four Gospels we have are the best ones, not the only ones.