I don't know what the answer is, but there is something to be said for retaining some beauty at the expense of fewer people, and maybe rethinking the idea that growth is necessary to success, 'cause we're running out of room and that definition can't last forever.
Change is inherent in a situation where you have however many billion people we have now. We are a dynamic system, and a huge one.
What you say is true, and also isn't anything new to the discussion. Change is awesome, and isn't even the point. It's more about the unsustainable quest for growth that is the foundation of our economy.
I'll let you argue with the "why aren't people having children any more?" people.