...
...If given a choice the overwhelming majority of men would pick the 20 year old young woman over the 55 year old mature and most likely infertile woman for a fun adventure...
... birth rates are highly correlated with living standard, that Asians and Africans - on average- get so many more kids than people in Europe or North America has little to do with western women being more prone to die in child birth...
...If you look at a country like Japan, the most developed country in Asia, then their birth rates are among the lowest in the world and they will soon face a severe population crisis...
To point A:
Of course the majority of men would pick a living person over a corpse too. The 55 year old woman is just a couple of years away from sexual inactivity, and few more from needing overall care.
I would be willing to bet most men would pick a 20 year old gardener over a 55 year old woman as well, and that has Zero to do with fertility. You are trying to tie fertility to age, which of course has a natural correlation; but you are completely discounting strength, ability and finite human lifespan in that same calculation. Of course a 20 year old is going to have more fertile years than a 55 year old, any by the linear nature of the arrow of time, they are also going to have more strength, ability and lifespan too.
If my 'Fun Adventure' was to catalog a library, or perform research on financial or scientific endeavor, you can bet your ass i would pick the 55 year old every time.
To your point B:
My wife just hit 42 and we are just now trying for a child. We waited until we were in the financial situation to be able to pay for things out of pocket, without going into debt. This has become not uncommon in the west, a world of wage-slaves, taking out life-crushing mortgages on their future as children, in a desperate gamble to have enough money so you don't starve to death in your old age. Undoubtedly, this has a tremendous effect on birth rate. But this has not always been the case, if we go back 1000 years to feudal times, and the late Roman period, there is a good apples to apples correlation in living conditions.
We have feudal serfs compared to feudal serfs, and the first large cities compared to the first large cities.
And the Asians win. Hands down. Song China had a population of over 80 million, The Chola Dynasty, 22 Million. India over 11 million. The Eastern (HRE) and Western (Byzantine) Roman Empire had around 24 million, but remember that both of these empires included all of Europe, Asia Minor, North Africa, and around the Iberian peninsula.
In apples to apples technology and lifestyle, that's 110 million to 24, and part of that 24 is Africa. They are better breeders.
To your point C:
Japan is a unique anomaly among the Asiatics, and it's 'wounds' such as they are, are largely self inflicted. The unique warrior path of zero tolerance for defeat encompassed in the code of Bushido, combined with the nearly complete loss of breeding alpha male genetics by the end of WW2, has produced an entire race shamed to the point of, and feeling an obligation to, national suicide. The words of the former emperor Hirohito, "must endure the unendurable" still ring in the Japanese mindset.
While those words were initially credited in western medias as having 'saved' Japan during the post-war resurgence, that has since proved, to my mind, a false narrative.
Personally, i believe that it was the survivors of that generation, who felt an obligation to the Emperor's words, and as that generation has died out, so have the fortunes of Japan. While their civilization remains clean, modern and unique among Asiatics, it became so under Emperor Meiji's Restoration, destroying the previous Feudal system under the Shogunate.
The Bushido mindset, of 'everything for my Emperor and my State before myself, to the point of death' did survive, and was weaponized by Japanese military. 25% of Japans male population died in WW II. These were principally front line fighters, the majority of which are comprised by genetically predisposed 'Alpha Males'.
A further 15 million of Japans fighting males never returned home after the war, out of shame of Bushido.
Japan effectively lost 40% of it's fighting age male population from the genetic pool. The remaining males were mostly elderly or so-called 'Beta Males', administrative, clerical, politicians, businessmen, etc. People without a predisposition towards fighting, and without those proclivities. These active genetic traits are also what makes good strong breeding stock.
The weak breeding stock, combined with the national shame and desire for suicide under Bushido, suppressed only by the Emperors command, delayed at best for a generation the inevitable outcome.
The Japanese male today is introverted, self absorbed, and focused on asexuality, to the point that the femininity has become the ideal for males, (J-pop type male stars lithe, weak and wearing makeup and lipstick), while the females perform the majority of traditional male roles, farming, building, etc. The average Japanese male today who marries at all, works in a white collar job, does not marry until age 47, and produces .02 children.
Less than 13% of the population is age 14 or under, 64% are 15-64, and 29% are 65+...
The Japanese, as an effective country, will cease to exist within 2 generations, unless forced breeding programs are established.
None of that has anything to do with their Fecundity however, and everything to do with a self-genocidal collapse based on a devotion based on an ancient code, which failed to adapt to a modern world.