Seems to me there is a cultural difference between Catholic and non-Catholic Christians and Jews with reference to the availability of theological information.
As a modern day example, a few years ago I read about the Catholics reaching out to the Jews for some kind of agreement in their desire to recognize the achievements of the Pope during World War II. The Jews who were appointed to the effort received a great deal of information from the Catholics who were appointed to the effort.
As I recall, the Jews were appreciative of the information but asked that the archives be opened to them so they'd be able to do their own research. But their request was declined and so they withdrew.
My speculation is that the information was simply information to the Jews but that it was sacred to the Catholics. Hence, I would call it a cultural difference.
Likewise, non-Catholic Christians would view all of the information banned by the Council of Trent or, for instance, the writings of Tertullian which have since been lost, as simply information. And the loss of such information might discredit the Vatican in their eyes, i.e. why not preserve moot or adverse witness but for fear?
Culturally, the manuscripts to non-Catholic Christians are simply manuscripts. The power is in the words of God themselves.
But in the eyes of Catholics, I suspect the manuscripts themselves are seen as sacred. Certainly in each Mass I attend, the manuscript containing the Gospel is kissed and held up before it is read. It is treated as though physically a holy object.
But everything happens for a reason. I am confident that it all works together for the good according to God's will.
Still, I'd love to have access to the lost manuscripts. But, alas, the Vatican is not a "Library of Congress" for the theological.
God's Name is I AM.
This is a good point to reflect on the consequences of the iconoclastic movement within much or the Reformation that was responsible for the wanton destruction of incredible Church art treasures. Prior to wide spread literacy the Gospel was taught and spread through religious art in the form of paintings, icons, tapestries, stained glass, sculptures, music and acthitecture. It was very much the same Word of God found in Scripture expressed in a variety of different media. It was was very effective, facilitating the greatest growth period of Christianity. Wouldn't you love to have access to those too?
Peace be with you