While it's a good to think about childcare, something more constructive needs to be done about growing up in the modern world than extending the caging of modern children.

John Taylor Gatto (iirc) advised keeping kids out of school as long as possible, as nothing important is learned in the first few grades that wouldn't be learned anyways, or couldn't be learned more efficiently later. http://johntaylorgatto.com/

If the government were to extend school-as-childcare, it could be done in a way that restores the ability of children to learn from the real world. I don't know what 4, 5, 6 and 7 year olds should be learning, but imho Pre-K, K, 1st and 2nd grade "classrooms" are stifling.

Gatto's essay, Dumbing Us Down: The Hidden Curriculum of Compulsory Schooling, is all over the interwebs.

What did Native Americans teach their 4 year olds?