Origen wrote that "The church has four gospels, heresy many", and Irenaeus wrote that there were only four gospels too, just as the earth had four corners.
So already by their time, c. 170-200, the narrative of Jesus was set in stone as four gospels plus maybe John's Revelation. Any other narrative of Jesus, even the Diatessaron, the Gospel of the Hebrews, and the Protoevangelium would therefore be excluded and rejected.
Another thing I notice is that outside the four gospels, the opening of Acts, and maybe the book of Revelation, there is no narration about Jesus. That's 27 books of the NT minus 6 = 21. I would have expected at least a few paragraphs to slip in narrating what happened.
It's true that Peter mentions seeing the Transfiguration and Paul has his brief Creed-like summary where he mentions James and the 500 seeing Jesus. But they are not really narrations. Peter and Paul don't give details. When we get to James' epistle, he says so little about Jesus that some skeptics have wondered if it was even written by him. For that matter, people even start to doubt that these writers knew of the virgin birth and if Paul's reference to the 500 and his Creed like summary were an interpolation.
It seems to me that a different explanation is correct - maybe they deliberately were quiet about these things in their letters. When it came to the narrative of Jesus' life, they presented their 1-4 gospels, and were otherwise deliberately silent.
So for example, Paul says in Gal 1:8:
But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
Now you can take that to mean that no one should preach a theology (the "good news") conflicting with the true one Paul originally gave.
But it could more strictly mean that no one, even Peter and James, is allowed to preach any narrative of Jesus' life separate from the official one. That would help explain why there are 27 books of the New Testament and about 20-30 books from the mainstream church in 35-150 AD, but little of it directly narrates Jesus' life except for the 6 books I named, maybe Papias' semi-lost commentary on Jesus' sayings, and semi-rejected or semi-lost works like Gospel of the Hebrews.