There is nothing wrong with it. However the reality for a lot of women is very different to the fantasy, it's not all rice crispie cakes and sing alongs, often it's screaming kids, mess, housework and abject loneliness to the extent a toddler group becomes a life saver.
In addition being out of the workplace for a long time can impact on ability to get back in, as well as dent confidence. If something goes wrong, from illness of a partner or divorce it leaves you horribly vulnerable, no one ever dreams these things will happen to them.
In addition no matter how supportive a partner is at the beginning or how important the role is stated as, often many women start to feel less, less than their wage earning partner or their wage earning friends, because they earn the money and the stay at home mum often feels they don't have as many rights to the major say.
Couple that with after a few years out, many women get used to it. Then they find their partner wants them to go back but they don't want to and lack the confidence. They don't want to go into a lower role and it starts to damage the marriage and resentment creeps in on both sides.
I met so many stay at home mums when my daughter was at school ( privately educated) and they all wanted to tell me what they " used to do" like in some way it kind of validated them, even though I hadn't asked. They raised it.
I worked throughout, and yes at times it was hard. But I never considered quitting and looking back now it was the right decision for our family. My career took off, financially we are much more comfortable than we would be and my 20 year old daughter asks me for career advice and she takes my feedback seriously, because I didn't do it twenty years ago, I did it throughout and I'm still doing it.
So where as you haven't asked the benefits, I think on the downside, it does have some negatives, that very many women have come to regret.