Surely whether it's "their most economically productive age" would depend heavily on how many children they have and how much parental leave they are allowed.
We know that people in most developed countries aren't even hitting replacement rate, so I don't think that 6 months of leave is going to break the bank.
In my experience, employees who are bad employees and blame it on time commitment to their children have usually been bad employees to begin with. I have a child, spend upwards of 4 hours a day with them on average, and work at a FAANG, while hitting promotion tracks more quickly than my colleagues without children. I know a bunch of people doing the same.
