This applies everywhere: just because a job or business has existed does not mean it has a right to exist forever. This is not being harsh on people; it's just a reality. The blacksmiths in the horse and buggy days saw demand for their services fall when time and technologies changed. The coal miners began losing their jobs when we realized that coal as fuel was more harmful than it was beneficial. History is full of…
Dinosaurs prospered for million years, you know? And only global scale mass extinction ended their reign.
So, though it appears we do are well on the road for such a huge collapse, I’m not sure your analogy was the best one here. :D