In my original country, the parental leave is 3 (yes, three) years. It only became available for both parents not so long ago, so generally the mothers will take it (even though it is becoming more and more common for dads to share, which is of course excellent). As only 1,5 years of it is paid according to your previous income, most people take about 2 years off. And you know, small businesses are doing just fine, everybody adapts and accepts that this is the way the things are - peole have kids and take time off.
Then again, the child care is affordable, schools have more reasonable hours, kids have more independence and parents mums are not expected to find a way to get to school gates in the middle of the day, therefore most women also return to work full time after the maternity leave.
So I think this is actually the main problem - as it is so expensive and complicated to work and take care of kids, many women decide to stay at home instead of trying to do it all. And many employers assume that they will do so. So this is the thing that harms women's career chances, not so much the exact lenght of the leave.
So yes, first the parental leave should definitely be availabe for both parents, it's ridiculous that it isn't. It will take some time before fathers start using it, even when available, so maybe even the solution like in some Scandinavian countries would be good (otherwise parents can share as they see fit, but some part of the leave is only for the father and if he does not want to take it, they will simply lose it. Paid leave, of course).
And second, the whole system is currently set up assuming the mother does not work or does so part time, this really needs to be changed if women want to be treated equally by employers. Please note that I'm not in any way suggesting that everybody has to work full time, but everybody should at least have this option available, so they can do wahtever is best in their particular situation. Which I don't really think is a case at the moment.