God authenticated his Apostles with signs and wonders. These same authenticated Apostles and disciples were inspired to write the new testament scriptures.
Once the God inspired most of what would be the New Testament and closed the canon the sign gifts petered out.
What you call Oral “tradition” during the time of the Apostles was written down within the lifetime of the Apostles.
Later novelties also called “tradition”, unknown to the Apostles and the early church was never authenticated by God via the sign gifts.
"Since many have undertaken to set down an orderly account of the events that have been fulfilled among us, just as they were handed on to us by those who from the beginning were eyewitnesses and servants of the word, I too decided, after investigating everything carefully from the very first, to write an orderly account for you, most excellent Theophilus" - Luke 1:1-3
Peace be with you