Balance of the world

I noticed a trend in different questions, when properly thought out, considered, and analyzed. they usually do not have an answer. Knowing this (or just learning about it now) why do people attempt to unbalance the world.

What would happen if someone does find a cure to all diseases? overpopulation, lack of food, increase in demand(everything)

What would happen if everyone was intelligent? there would be no people working in factories because it would be boring or just "beneath their intellectual ego"

What will happen if everywhere, there will be peace? technological advances always occured the fastest during periods of war.

I would love to hear your comments!