Historically, 10% of women hit menopause childless. In the U.S. and much of Europe, it is currently 20%. Some are naturally sterile or choose not to have children, but a large number are involuntarily childless. They prioritized career and politics, then tried to find a partner when they’re past their prime. A few are single mothers by choice.
And many ended up alone while blaming men for not being interested in a 35 year old independent feminist relative to the 25 year old one without baggage.
Of those who do have children, biology means most have one child instead of the 2-3 they wanted. And others are single mothers who have just one, whereas if they had a devoted husband, it would be 2 or more.
And they are saying, "Screw that." Even if they do have kids, they want nothing to do with having more that 1 or 2.