I think Paul, because he was Saul, was an outsider for many years and this allowed God to work with him one on one. And clearly God was pleased, Paul, became more Authoritive than many of them and wrote 2/3 of the New Covenant.Ah, I see.
The letter's scope was very narrow. It only addressed the issue of circumcision and the law:
But some of the sect of the Pharisees who believed rose up, saying, “It is necessary to circumcise them, and to command them to keep the law of Moses.”
The letter the apostles and elders created began...
"Since we have heard that some who went out from us have troubled you with words, unsettling your souls, saying, “You must be circumcised and keep the law”—to whom we gave no such commandment—"
This was an answer to the judaizers who were mixing the law with their faith in Christ. The young saints certainly required more teaching than this.
eventually, Luke, was following Paul + Paul had Disciples.
It would have been nice if we had writings from all of the Disciples. Been interesting to see more miracles that John claimed in his Gospel that were too many to tell and would fill up all of the libraries of the world.