Even if the wife doesn't work outside the home, if they get divorced in a community property state, they both get 50-50. If there was any abuse or infidelity, some states will grant more to one side than the other.
Spousal support or alimony is available in some states, too, if one spouse needs financial assistance.
Even if custody is split, which is not a guarantee, generally whomever makes more money will have to pay child support.
Everyone loses in divorce, especially children.
How well do I know all of these things, especially the latter.
Yes, property is generally split 50-50, but my point (probably more implicit than it should have been) was that, in modern two-career marriages, each spouse makes roughly the same salary, and can be presumed, if they "started out with nothing", to have contributed more or less equally to the marital estate.
Split custody is becoming more and more common, but in our society, as a practical matter (especially in more socially conservative parts of the US) the mother is presumed to be the more "natural" parent (regardless of her suitability for it), and the social expectation --- which is pretty malignant and damning --- is that the father is some kind of wastrel who will inevitably seek out another partner (due to various promptings in oneself), and his paramour takes precedence over his children. The end result is that you have a social system that indirectly enables stepfathers, and can even put them in the role of the dominant male in the children's lives. Thankfully, I was spared all of this, and I have been far and away the dominant force in my son's life from Day One. Being retired and able to homeschool him full-time is just icing on the cake. And there is no stepmother.