Since Jesus spoke Aramaic and so did the disciples, why wasn't some of the NT books written?

Contrary to what some people have written, Greek was the language of the urban elite, it was not commonly spoken by the subject populations. It seems to have been written in Greek because the followers of Jesus were gentiles rather than Jews. Most of the writings written by Jewish followers of Jesus' message were destroyed later by the church, because the Ebonites, Jewish "christians", believed that Jesus was a human messiah or prophet not divine. They were also religiously Jews following the law and offering sacrifices at the temple.