We actually have a lot of manuscript evidence defending the text of the Bible as we now possess it, far more evidence than for most other historical documents. This is a wonderful way to demonstrate that our modern Bible reflects the original biblical documents.

At the same time, we don't have the original texts of the Bible, so we have to admit that our evidence for the Bible is somewhat weaker than the evidence for some other original historical documents that we actually do have. For example, we actually have some ancient covenant boundary-marker stones that are older than any biblical manuscripts we possess.

In any event, the most important question is not, "Is this piece of paper more reliable than that rock over there?" In many respects, it doesn't matter if the rock or another ancient document accurately preserves an ancient record. What's important is that the original manuscripts of the Bible were true, and that the manuscripts we now have are accurate representations of the originals.