I think having a smallish mortgage and no debt helps.
DH earns around 18k and I'm a SAHM. In reality we don't actually have a small mortgage (bought house at market peak a few years back) but we switched to interest only a couple of years ago because basically I had PND, was off sick from work and now cannot get another job in my chosen profession. Interest only is generally thought of as a mugs game but to be honest it's enabled me to SAH with the kids and not worry about working.
DH and I are relatively young, and even if I was to have another 5 years off (which is what I'm planning) then I still have a good 30 years to pay off the capital before I retire.
We don't have luxuries, no holidays had for several years, either abroad or caravan etc in the UK, no Sky, second hand clothes, no takeaways, no alcohol (really, none), and a house with stained carpets and a sagging bed because the only way we could replace them now is by getting into debt (which is not an option, debt is for emergencies only in our house!) (except the fucking huge mortgage!
)
So no, in my world we don't rely on my income, but it took some serious mental health issues to get here and a lot more on top of that. It's not always rosy to be honest and I appreciate, OP, that it's lack of choice in a lot of people's situations. But theirs lack of choice in mine too. I'd love a three day a week job where I could nip to Tesco's on the way home and buy a bottle of wine without thinking about it. But since I had six months on the sick and was 'let go' by my employers on sickness grounds, no one will touch me with a friggin barge pole 