Do you believe that God allows the corruption of his word?
In fact, I do! Why? Because we are fallen. True, Christ has saved us, but we are not perfect or glorified. That is why the earliest manuscripts are more accurate, because the hand of imperfect people has touched them less. The Byzantine manuscripts have all been logged and the mistakes charted through families. The errors are well known, in every one of the 4 families. Constantly, the other 3 families tend to agree with one another, when compared to the Byzantine, too.
On the other hand, God has preserved the Bible, by allowing well studied and humble men to compare texts, to find the errors and eliminate them. Is the Bible accurate? Of course!! Is it perfect? It cannot be, as long as men are involved.
Your faith in the perfection of the KJV is pure and unadulterated magic. God knew from when Adam and Eve fell in the garden, he would have to arrange to have the best possible manuscripts be discovered. Daniel Wallace was given permission to go into the libraries of Constantinople, (Now know as Istanbul) and Greece and photography, copy and name every unknown manuscripts. His goal is to find the original autographs, which God may make available as we grow closer to the return of Jesus. If not, he has still found thousands of new manuscripts, older, better, or perhaps newer and even more corrupt, for scholars to ponder for decades to come. With computers, this job may also be much easier than it ever was.
There are over 6000 manuscripts of the Greek NT extant. The KJV used 7 corrupt ones. It baffles me how someone could ever believe the KJV could be perfect. God says his Word will be preserved. For me, right now, that is the NET in English, the Revised Martin Luther Bible in German, the Septuagint, which the disciples and Jesus quoted over 80% of the time. And funny how the disciples and Jesus never got hung up on whether the Hebrew or Septuagint were more perfect versions. No, they just quoted both, although the Septuagint was used so much more in the first century, because besides Aramaic in the NME, Greek was the common language of the Roman world, reflected in the word, Koine, which means common.