The world is overpopulated (by humans, that is). This is a fact, although there will be some who dispute it. We people are causing all sorts of environmental damage, much of which threatens our own existence. So reducing the birth rate sounds like a good thing, and to an extent it is, in my opinion. The birth rate is steadily declining worldwide which contributes to the slower growth rate in the population. There is still a positive rate of growth due to reductions in the death rate, especially among children.
Within the United States the fertility rate (number of births per woman of childbearing age) is about 1.7. This is well below the replacement rate of 2.1, and most developed countries are also below the replacement rate. There are only six countries in the world with rates above the replacement rate. Four of those are in Africa, one in Micronesia, and one in central Asia. The population of the US is still increasing but mainly because of immigration but also due to lowering death rates, mostly among the old. Experts predict that by 2050 the worldwide fertility rate will have dropped to the point where deaths exceed births and population levels off, then begins to decline. This will be great for the environment and other species, like fish.
But what happens in the long run? This is where it gets tricky and we see politics, religion, and moral beliefs muddy the waters. The death rate has to level off since people must eventually die. It can’t reach zero. That means if the fertility rate continues to drop, or just stay below the replacement rate, humankind will eventually breed itself out of existence. There are people who worry about this, and it is not a trivial matter. A few may think that’s not such a bad thing, but most people would disagree with that. Personally I think it’s a valid concern, but I don’t believe that will come to pass. I believe it likely that when there is plenty of arable land per person, birth rates will go up again. Now with automation, a relatively few farmers would easily be able to feed the world. Those who want to can easily grow crops or raise livestock enough to feed their own families. I think there will be enough women who will be willing to have more than two children that an equilibrium will be reached. I foresee a sort of automated hunter-gatherer society emerging.
But one thing seems certain: the future world population will look quite different. In particular, it will be darker. The fertility rate among dark-skinned people, especially Africans, is much higher than among the white and east Asian people so their representation in the future population will be higher than it is now. I believe this fact is behind the so-called white replacement theory. That theory is a false, racist theory believing there is a plot, probably led by the Jews, to cause white people to go extinct. That is ridiculous of course, but there is a kernel of truth in it. The white race will go extinct, or at least darken, but it will be because white women will almost certainly continue to choose to have fewer babies than the darker races, and more intermarriage is inevitable. I see no problem with this.
The bigger problem is the imbalance in ages. Older people are continuing to live longer during non-productive years, causing younger people to work more to support them. Most species have their older members die off once they are no longer reproducing. This would be more efficient for humans, too, but I don’t see any way that is going to happen. Older people control most resources and governments and will not willingly agree to die faster. This may become permanent.
Finally, I believe this will all work out in future generations. As the population drops, there is more wealth of all kinds available to each person and there will be less need for both spouses or partners to work. Crime will drop and quality of life will be high. This will be many generations in the future. Women are already beginning to find liberation to enter the work force is not always as rewarding as they once thought and the rewards of motherhood are high. Women’s liberation was a good thing and should continue, but that ceiling has mostly been broken now. I see more and more young women drop out of college or graduate school, or quit working after a few years of the daily grind and choose the mommy route. They should have the choice to do either. I’m hopeful the fertility rate will eventually come back up; just not yet. For now it is more important to mitigate the environmental harm we are doing. Religions are certainly pushing for more babies. I think consciously or not, that is the motivation behind the antiabortion movement. It really has nothing to do with saving souls.