Yes, Catholics wrote down their oral tradition and protected it via the magisterium.
Let’s go to a higher authority. What does Jesus say about traditions? Will you accept this authority? What is Jesus saying here?
Pay attention to the words, substitute, sidestep, cancel, violate. I believe in the Holy catholic (universal) church. These words apply to all of us.
(Mark 7:9) Then He said, “You skillfully sidestep God’s law in order to hold on to your own tradition.
(Mark 7:13) And so you cancel the word of God in order to hand down your own tradition. And this is only one example among many others.”
(Matthew 15:3) Jesus replied, “And why do you, by your traditions, violate the direct commandments of God?
Catholics wrote, compiled, canonized, and protected the NT via tradition and the magisterium.
2 Thessalonians 2:15 - So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter.
2 Thessalonians 3:6 - Now we command you, brethren, in the name of our Lord Jesus Christ, that you keep away from any brother who is living in idleness and not in accord with the tradition that you received from us.