It leaves them economically vulnerable. When 100% of the income is going into one person's bank account that means they have the opportunity for economic control over their partner. Their partner does not have savings of their own to speak of. No, healthy relationships do not work that way. But a lot of relationships do.

Also, it's often not "through choice". A lot of the time childcare is more expensive than one parent leaving their job. A lot of families can't afford an alternative.

Which would completely ignore the economic imbalance I was talking about, which occurs during the marriage.

> It's 2026, and women are starting to outearn men in some cities. Why make men the sole breadwinners of the family?

Like I said, making a parent a stay at home parent is simply economic reality for many, while the kids are young and childcare is expensive. There’s no reason why that has to be the woman but the data shows that the vast majority of the time it is.

Even if one party earns less, I don't see how "vulnerable" that would make them if it was prior to meeting the other person.

The topic was couples/cohabitation/marriage, not the economics of child rearing. The concerns you raise would be equally applicable where the parents have nothing to do with each other. There is truth in what you are saying, but it is an entirely different topic. How to deal with the child is a negotiation that takes place around the child, not around a romantic relationship (or lack thereof).

In the romantic relationship, there is no realistic situation where one party ends up with all the money unless one is being 'stupid'. But any of us can be stupid. I could willing give you all my money now and there would be no good legal recourse if I decide it was a bad idea later. The only reason we have these ideas is due to the historical idea that women need protection because they are unable to make decisions for themselves.