this is paid leave (it's only an allowance, not usually a full salary though). Where I live it's up to a year for a father, but most of them do not take it since we are still entrenched in the "father at work/mother at home" society
It’s the age old conundrum of what is good for society versus the individual, and how an immeasurable benefit (fathers spending time with children) can lose out to measurable benefits (fathers being able to sell their labor for a higher price due to having more experience/getting promoted since they didn’t take parental leave).
The other benefit of forcing fathers to take parental leave, would be to help equalize the playing field for men and women. But then the country may lose a competitive advantage to other countries since their products might be cheaper since they have a greater supply of labor, but in the long term it would be beneficial for the world to have mothers and fathers both spend time rearing children, however it unquantifiable unlike their cheaper products resulting in higher exports.
If its not paid by the parents, who is paying for it? It often is a mix of co-workers, consumers, and taxpayers.
What society is and can be changed is one thing, what you do by making that society ilegal is another one.