The household, as a live, dynamic thing, requires constant upkeep and endless work, from the most routine to once-in-a-while projects; there's always something to wash or clean, cook or bake, make or mend, plant or grow. And, most importantly, there are the people living in the house - each of them a unique individual with their needs, wants, hopes and dreams.
When you live in your home full-time, there is undeniably more mess and upkeep involved than if the entire family steps out of the house in the morning and returns in time for dinner, being present only on evenings and (maybe) weekends. But a lot of work accumulates anyway. Clothes are worn, meals need to be made, dust settles down on surfaces.
If you have a garden or pets or some livestock, it is even more so. Even while you are away, weeds keep growing, chickens keep laying and pets need to be fed and taken care of. Whenever I'm away from home for a couple of days, or we spend a couple of days on errands, I find myself rushing to catch up later: weeding, mucking out the chickens, picking up stray items blown into our yard by the wind (the winds are pretty strong here, so we get all sorts, from snack wrappers to plastic kiddie chairs).
But of course, most important of all are the children. There are simply no short-cuts here: while housework can be put on hold, children must be looked after. Someone must do it... and that someone is usually a woman. Daycare centers, preschools, kindergartens are all staffed overwhelmingly by women (I've never even heard of a man working in a daycare center or preschool, at least not in Israel). In schools, too, most of the teachers are women - the younger the kids are, the more pronounced this is. That is because young children respond best to a motherly figure... who, ideally, should be their mother.
I do realize that in some circumstances even mothers of young children must go out to work (though in many cases, creative solutions can be found and sacrifices made in order to provide a full-time at-home caregiver for the family). However, one must remember that this isn't an ideal situation. Just a couple of generations ago, it was a matter of course that a married woman with children, whose financial circumstances are not so constrained that she absolutely must work for a living, will stay home with her children (and no one would ask her what she does all day long).
I find it especially ironic, and a little sad, that mothers get up in the morning, put their babies in daycare and go off to care for other people's children: they outsource their children to someone else, while making their living off other people who also outsource their children. Financially, economically it might make sense, but in straight thinking, emotionally, socially, it would be a lot better if everyone could simply take care of their own children (who were give to us by G-d to raise and bring up), perhaps occasionally relying on help from extended family such as grandparents and aunts.
It's crucial to remember that at any given moment of the day, someone is taking care of the children. Their parents, or someone else. The children are well-cared for - or not. Happy - or not (though present happiness is no indicator of good upbringing). Well-nourished - physically, mentally, emotionally, spiritually - or not. Recently, two children in a local daycare center were found playing with a dead mouse. Apparently they had been playing with it for a while before someone paid attention. I'm not saying blunders are inexcusable, but there is a heavy price to the efficiency of a group of children herded together all day long - the inadequate, impersonal care too many children are getting; the generation of overburdened, overstretched, overworked women.