In Germany it is the parents who get the leave and they can freely decide who takes the 12 months of it. Even better yet: If they decide to split they get an extra of two months, so 14 in total.
There are many reasons, it seems to me that external circumstances are shaping a lot of them.
edit: To expand ultimately societies and governments need women to have kids, as of now they're the only ones who can after all so I think eliminating as many downsides as possible to that is something that should be done.
I think that this is much better to left it to parents to decide how to split that based on their personal preferences, than to force equal split in all cases.
As parental leave is a legal right (not given by the employers), employers simply have to comply with the parents' wishes. In the past employers often frowned upon men taking parental leave, but the younger generation has absolutely normalized this behavior.
It should also be noted that during leave, the government picks up (part of) your regular paycheck - so you don't cost your employer anything while you're not there. (except administration overhead etc)
The parental leave doesn't have to be taken in one block and you can also convert it into 'parental part-time'. A somewhat common pattern that double-earning professional parents choose nowadays that I've seen with some of my team members is something like: 1. simultaneous leave for both partners in the 1-2 months after birth 2. leave of one partner for a few months after that while the other partner works full-time 3. a few months of simultaneous part-time (e.g. 3/days week) where on any given day, one partner is at home 4. full-time work of both partners for a while once the kid is old enough for day-care 5. another month or so of simultaneous parental leave after 1-1.5 years that's used for a vacation.