But, as I understand it, these processes only work with what DNA is already there. It does not create anything new, per se, just manipulates what is already there. It works by the manipulation of what already exists. You talk as if what would satisfy you is the spontaneous appearance of a genetic sequence out of thin air. This doesn't happen.
Gene duplication is a big way new material is produced for mutation to work on.
Had you bothered to really read the article I provided, you would have noted that many gene duplications were involved in that process. New information can arise when mutation works on that material, by either base substitution, deletion or addition, further internal gene duplications, are transposition from other sequences. So there are your processes. And the paper I provided detailed many of these processes. So I really do not know what the point is here.