In those days GIANTS were HYBRID HUMANS that thrived and lived wicked lives. Created by the mating of human women with fallen rebel angels. God sent a great flood to destroy all life that were wicked & perverted by these fallen angels. But God saved Noah and his 3 sons and his wife and his sons wives from death. And animals, a male and female of each kind. To reprocreate and populate the earth with a clean DNA of life line.
The Prince of darkness Satan and his minion fallen angels planned and plotted then and even today thru out every human generation. Even from Adam & Eves day evil has planned and acted to pervert humanity.
https://youtu.be/665ZSNZw9U0