Yes, everything you said is good, and we should be attempting to restructure our society to be more sustainable and ethical in our use of resources but that is a much larger political discussion about economics. I know there are currently natural and sociopolitical phenomena that are slowing down the growth of certain regions but the reasons why is a much larger, multifaceted discussion. Populations will fluctuate naturally and that's all fine and dandy.
but my point was specifically against those who call for attempting to steer the process in an effort to deliberately reduce the population through planned means which is intrinsically linked to eugenics arguments when you get down to the sociopolitical mechanisms of how that will be accomplished.