EverApostate; "So, Noah and only 8 of his family were righteous in the whole world ?"
Unfortunately at that time because of Jehovah God's kindness and generosity and liberalism He had made it possible for people to live about 900 years in warm nice climate. But that evidently just gave people more time to harden in their sins and wickedness to the extent that only 8 persons were willing to obey God.
In addition God allowed angels to go against His will and come down to earth and live here. And that only accelerated the wickedness on earth.
So to change all He brought a world wide flood to change all. To make life harder on earth with scorching summers and iceing winters. And he removed the moisture in the atmosphere that protected the earth. I think that lead to a greater cosmic radiation that shortened the lifespan of people. Maybe under the crust of the earth there was also a layer of water that protected from radiation from earth's center.
Yes, in fact usually when people live trouble free life they loose their interest in God. So all the harder life conditions and shorter life span has helped humanity to stay interested about God and his will.
Sad that we humans need hardships to stay alert against our own sin.