If they both want to work, then child care should be affordable for the dual income family. Generally it's not which is why schools are required to fill that care gap and be in sync with working hours.
There's a bit of a math problem there, though. It's hard to make things work out so that the child care is affordable for the parents, the teachers get reasonable compensation, and you're meeting reasonable (and, depending on where you are, legal) standards for child-caregiver ratios.
Doubly so if "affordable for the parents" means "affordable for parents who are in the same income bracket as your average pre school teacher."
True, although kids are only of childcare age for a few years, so if all adults share the cost burden of childcare for everyone throughout their working lives rather than just paying for their own needs for a few years, the math works out a lot easier. (IE, childcare paid or subsidized by the government.)
The other piece of the puzzle though is that there need to be sufficient providers, which can't happen instantaneously. So you'd have to scale up such an initiative in a sensible way.
