I never married and have no children or grand children. but the doom and gloom you fear is the same as that spoken of in the 1840s when we did not have the technology we have today.
Again, using it for advancement rather than death and war is a matter of choice. Obviously, war is profitable and that's why tech isn't used properly.
That doom and gloom came to pass. Part of the doom and gloom predicted would be that there would be increasing levels of warfare as civilized nations fought over ever shrinking availability of living space and resources in increasingly viscous and blood thirsty wars until they annihilated each others populations to the point there was enough room.
Sound familiar? Its what happened and what very nearly got much much worse. Its still only on pause, it isn't fixed yet.
From European wars being about honour, fought with rules and civility we had total war breakout.. and what types of things were fought over? Lebensraum, living space.
The Food problem is also not "solved" the 1975 problems are still there.
The "green revolution" is based upon using limited resources for temporary food boom. The energy used producing food is now something like what, 2000 times greater than produced? Before you produced more than you expended. Not only that, the processes needed to fuel this type of farming cannabalize available land, for the long term, ruining it.
This is like saying "See I can easily make more money, look I just pawned my couch, I can afford this new car" , It just means once you run out of things to pawn you are going to be more hosed than you were before.
This cannot continue.
I have yet to hear a good reason WHY we need 25 billion people and growing on the planet, What is wrong with five billion, or three billion?