I find this debate very difficult, even though it has been discussed on MN a million times. So I am not stating any definitive position here, just thoughts.
I am not sure whether looking after children at home historically was ever considered as "work". Except perhaps for professional nannies employed by the very rich. I really struggle to think about a time in history, perhaps with the exception of some kind of rosy picture of the 1950s, when all women did was clean the house, cook and take care of the children. In normal circumstances, poor women will be cleaning, cooking, looking after children, but also tilling the fields, milking cows, feeding livestock, spinning (often on the go), weaving, sewing, making preserves, making baskets, repairing their homes, etc, etc, etc. Rich women would be supervising large households, planning events and doing accounts. So yes, I question the assumed historical normality of our present conception of a SAH parent.
Mind you, questioning the normality is not the same as questioning the desirability. It's none of my business whether people stay at home or not.
I am all for making childcare more affordable to more people because it allows people to become more financially independent. And work is not just money but also a chance to interact with the outside world, to build up skills that may be very useful in the future. Community childcare is also historically normal as children were commonly looked after by people other than the parents (grandparents, older siblings, neigbours, etc) while the women did their milking and tilling and going to market/well.
And yes, I completely agree that the absence of the living wage is a crime.
I also think that the difference between WOH parents and SAH parents is waaay exaggerated. Lots of people move in and out of work. And once children are at School (4 years old in the UK), the difference in childcare hours put in by SAH and WOH parents becomes rather minor.