I think pre school children benefit from having a parent at home as close to full time as you can economically manage. I think primary school children benefit from having a parent who is flexible enough to be there to drop the children off, pick them up, help out in school, attend plays, appointments, sports days etc. I think family life runs better if one person is able to be at home before the other to do the chores so that family time is not absorbed by housework.
Beyond the time of breastfeeding there is no reason why this should be a woman, or even why it has to be one parent or the two parents sharing the role.
The first time around I was the person who stayed at home, mostly because dp was not around until dd was 2 and I was also not well enough to work.
I returned to work part time when dd was 4 and we had a year where we both worked full time. We were crap parents beacuse of it. I used to bundle dd in a car at half six in the morning to go to my mum's and would start worka few minutes later ( my school was at the end of the road). Sometimes dp would pick up dd from nursery at half five and I would get home for about half six, seven. I would then sneak a quick meal before dong some housework and working until late in the evening. Dp would spend his evening looking after dd, doing housework. Our lives were chaotic, dd was ignored by me and there were real problems between me and dd and me and dp.
We were bad parents, but I was no worse of a parent than dp. As a family unit we were failing dd. This was made worse by the fact that I have an illness which means there are times when I need support and I get tired very easily.
We addressed it by both of us making changes it is not just down to the woman.
I now work in a less challenging school and took a demotion. I now have one day a week where I do not work, no matter how much I have on. Sometimes I break this but I have to do that in a manner that does not affect dd. SO this morning I was up at 5 working while everyone else was asleep. Dp now works from home, part time and now does a good 90% of the housework. He works entirely around dd. He picks her up, drops her off, attends all the school events etc.
It has not been easy, we have less money to live on. Last year we had a lot of money problems and there were times we nearly lost everything and we struggled to put food on the table. But we knew it would be worth it. Neither of us are on huge wages, I am on a teacher wage and dp as he is part time beings in less than me. One of the sacrifices was having our own home. We are now in a rented house, although I hope that in a few years we may have saved enough to buy.
I think we are now bloody good parents, but that has been achieved by looking honestly at what we were doing wrong and facing it as a team, rather than dp saying to me "You woman stay at home , me man go out to work."
I work full time and am a bloody good mother, because I am part of a team.