They would do the translation and then it would be read out loud to see how it flowed.
This was a time when most people did not read (books were expensive!) so things were read to them. The end result was that thing that were meant to be read to others were written in a way that allowed the words to flow and (not incidentally) stick in your mind. Things that were meant to be read silently were written in a different manner.
I have heard that Shakespeare worked on the KJV, which would explain the literary qualities. It is also clear that many newer translations are the work of scholars who may know the languages of the Bible, but they don’t always know how to make it flow.