Personally, i will rather support the opinion of decongesting the spaces we are already populating and make use of the spaces which are still unused, rather than reducing the world population.
If we say the world's population should be reduced, the question is "how ?". Rumour mills have it that there are ongoing programmes aimed at reducing the world's population. Only time can tell if they will be sustainable.
I will go through the books you have cited and learn more.
Thank you so much for opening my mind on this topic.