Urbanization alone has long been observed as causing a drop in observed ferility rates as they no longer get the useful free labor investment, space is more exp

Urbanization alone has long been observed as causing a drop in observed ferility rates as they no longer get the useful free labor investment, space is more expensive and they are no longer self sustaining. Low sperm count is not the reason why most people do not have three plus kids - it isn't like people give up on birth control at 30 or 40 and never have any kids again. Most of is "won't have more kids" as opposed to "can't have more kids".