Read the Book Tragedy and Hope by Caroll Quigly. It predicted all of this. What we are seeing if the after effects of a post industrial society. As a nation becomes richer and develops the birth rates and marriage rates go down. There is four stages in the Demographic cycle. In primitive societies you have a high birth rate and high death rate. Your numbers are basically stable. The next stage is the beginning of industrialization. In this stage your birthrates are still high but you death is falling. This leads to a population explosion driven by advancement in modern medicine,sanitation and food security. This is what the west was from 1880-1980 and the non western world after 1940. 1940 the global population was 2 billion. Now its 7.8 billion. Right now where the west is the next stage of the demographic cycle is where birthrates are falling and the death rates are low. This means the population went from rising to stable. With rich countries the marriages rate declines. This explains why people aren't dating. The whole GMB phenomena is traced back to post industrialization. A lot of men in the west do not see an incentive to get married. Secondly women are more focused in their careers which means in their prime years (21-27) they do not look for husband. When they are in their late 20s and early 30s they are scrambling to find a husband. And if they do find one somehow they have children way later in life. Which means she will have one or two children at best. Feminism is an effect of post industrialism not a cause.
Add the growing incel culture, over consumption of pornography alot of men are taking themselves out the dating game. Another factor is that the standard of living is so high meanwhile wages remain stagnant or decline. This is why millennials aren't getting married as much or delay marriage. Student loans, credit card debt, ridiculously expensive real estate, gig jobs are all factors why people aren't getting married as much, aren't having kids as much. It is very expensive to have a child. Some people simply can not afford it. Again this the effect of a post industrialized society.
So what is the next stage after this? Well its what Japan is experiencing right now. You have a geriatric society. This where your birthrates are low and your death rates are rising. Your numbers are falling and the age distribution is skewed to older people. The main point in the book is that a rising population will take over a declining population. Why do you think right wing white nationalism is getting popular in Europe and the US? White birthrates are declining meanwhile birthrates in Africa,Middle East, and Latin America are growing. Africa,Latin America,Asia Africa are on the second stage of industrialization meanwhile the west is heading towards the last stage. This is why in those areas especially in the mideast, Latin America and Africa you don't hear they do not have these issues. Men still date and the birthrates remain high. Once you are a rich and fully developed that is when all the issues I mentioned arise.