Not true at all. Deception and fighting went on even during the years of plenty and excess. Human nature is not dependent at all upon material abundance; in fact, such abundance makes us forget about God quicker.
We have NOT had true plenty and excess for all of recorded history. Endless food, land and perfect climate for ALL. Such a concept is so far removed from our current view of the timeline that we cannot even comprehend it. Yet, every culture STILL has stories passed down from the times of “Eden”.
We simply ran out of such perfect places on this planet. Not enough land and fruit for us to simply frolic in nature without using labor/force. Then our minds slowly evolved to fight over these things for hundreds of thousands of years. Through thousands of wars and genocides fought over land and food.
But once you strip that all away and make all we fight for irrelevant, you see Love and the sharing of it is the true primary desire of man. It will all re-emerge in a future chapter