Saying that the patriarch lived a long time was a way of increasing their stature in the eyes of the faithful. It was not to be taken literally.
Using that logic, we can dismiss as not literal the entire scripture! 6 days, burning bush, Jericho, Goliath, Elijah and fire from heaven, feeding of 4000, raising Lazarus, Jesus' resurrection...
Who get to decide what's literal?
“Saying that the patriarch lived a long time was a way of increasing their stature in the eyes of the faithful.”
Which then makes the faithful morons?
There is no reason to believe that the ages of the patriarchs were not meant to be taken literally. Those who study aging believe that there really is no reason why we are limited to living no longer than 120 years, other than the fact that we are.