Parental leave as currently implemented in European countries incentivize having children later in life which is happening resulting in less children overall. There is absolutely no reason employers should be burdened by parental leave. If we as a society decide we want to support parents let's collect enough taxes and have the government pay. If the support is independent of your job status and salary it will remove twisted incentive to wait till your 30s do have children (which is the case when benefits are based on your current salary).