The Bible was compiled and evaluated gradually over centuries by thousands of priests, rabbis and bishops. The OT canon was established in practice by the time Christ was born, and the NT canon was all but universally accepted by AD 150. The fourteen disputed books included four gospels which are perfectly orthodox but were not considered inspired, the Didache, and two more that are orthodox in theology and all moral points but wre finally considered not to be part of the actual Bible; these are still in use among Christians and always have been. They were written in the late First and early Second Centuries and attest to the continuity of Christian doctrine, morality, history and practice.
The seven that were finally accepted as canonical had always been accepted by all Christians as true – there was just a small scattering of early Christians who weren’t totally sure they were Scripture per se. These did not include any of the Gospels, all four of which had been universally embraced from the very start, but they did include Revelation (Apocalypse), the Second Letter of Peter, and a few other epistles. The distinction between actual New Testament Scripture and mere good teaching materials and inspirational writings was understood, and all 46 OT books and 20 NT books were 100% accepted as Scripture by the early Church, but there were minoritydisputes over those fourteen. The issue had nothing to do with the reliability of the fourteen books, just their canonicity. The historic evidence shows that the faith did not change from the time of the Apostles to the present day.
The first printing took place in the Middle Ages, when printing technology was there to use. Translation into various languages went on continually. The first English Bible was transalted and printed by the Catholic Church.
All the Reformers did was to speed up the process of getting Bibles translated and printed, and did so at the expense of editing. In some cases, this turned out to be worthwhile – it allowed affordable Bibles to be sent to the whole world. But it isn’t the whole Bible.