There have always been prophets of doom. Thomas Malthus predicted that over-population would exhaust our resources by the end of the century. And that was two centuries ago.
Mankind steadily progresses, building on our learning, our methods of production and our technology.
The doomsayers are quietly left behind. But in politics it's different. A little bit of doomsaying makes sense. Expect the worst and try to prevent it. Our Founders wanted to contain political power.