Reader Alpha emailed to let me know about this French article that indicates that many more men are childless in France by 50. The article is in French so he kindly translated it for me and I put it in google translator to get the headline. Here is what the reader said the article was about:

The article says that while 12,8% of men born between 1941 and 1945
had no children by 50, today, 20% of those born between 1961 and
1965 are childless. Meanwhile, the percentage of ladies without
children remained broadly the same at 13,5%, as it has been since the
1930ies. There has always been a discrepancy between genres, due to
unrecognized children. However, there is clearly a trend with males
now, and the article says that while only 5% of the seventy years old
have never lived in a couple, 10% of the fifty years old haven’t
neither, mostly by choice (and only 7% of the 50 years old women have
remained alone all their life, indicating that the choice to be alone
could be more attractive to men). Moreover, social status has an
influence : by 50, about 12% of the employees, farmers, and laborers
have never lived in a couple and 27% have had no children, while only
7,5% of the executive have never built couple and 17% remained

It would be interesting to do a Men on Strike book studying French men to see if there are differences or similarities to American men in why men no longer have children or relationships as often.