Mormon’s lack of hope is unfortunately the better predictor of the ultimate fate of the Nephites. The Lamanite army appears to be increasing in size. This would suggest that as they have moved through the Nephite lands, many of the people of those lands shifted allegiance to the army that was clearly going to be the victor. Such opportunism was a matter of survival for many.
The Lamanites come with an army that is apparently even larger than the army that was so large it could not be counted. There is doubtless slaughter involved on both sides, but the shere weight of numbers is clearly on the Lamanite side. The end is now upon the Nephites.