In many cases it's not precisely "make companies support parents", at least not directly. In many social-democratic countries, companies are required to accommodate the parental leave, in the sense of allowing the absence, but the pay during leave is funded by the government, via taxes, not expected to be covered by the company on its payroll. It's considered part of the social security system in those cases, like old-age pension, free schooling, and other such universal, state-funded benefits.