The market is better at 95% of things than government. Especially when the government is any form of amoral democracy or republic. But, given what we know about what close/strong families can do for a society, I don't think you can compare encouraging that vs. some productivity numbers.
To be clear, paid leave isn't a cure-all, we're a rotting society that needs all kinds of fixes. But, I can't imagine how family bonding in early childhood would be a net negative, even when taking into account the economic downside.
We have varying levels of paid leave as it is. More progressive companies offer extended paternity leave. It's a global market and US companies have to compete with European companies that offer up to a year of paid leave.
The market itself will fix this issue.