When my wife and I first got married 12 years ago, we would have found it very difficult to survive financially without her income because such a large percentage of my income was shipped to my cheating ex-wife for child support.
With my ex-wife's husband's income and her child support income from me, she was able to be a stay at home mom for her new children without taking a financial hit. If she'd have earned an income that was more than the equivalent of a full time job making minimum wage, the amount of money I gave to her for child support payments would have decreased.

Meanwhile, my wife needed to work full time in order for us to have the financial means to have children of her own. Before we got married, I lived with my parents because more than half of my income went to child support. That's what happens when a guy loses his job. Child support payments fall behind and when income is restored, the ORS will take half of each paycheck until their is no longer a debt.

My income finally shot back up again over the years and we're to the point that we could probably make it without my wife's income. I'm not sure.

Meanwhile, my oldest son (senior in high school this year) got tired of his mom's mind games last fall and moved in with me. To make it a little more fair financially, my ex-wife returns a small portion of the monthly child support payments she gets from me via the ORS. Of course, she should pay child support TO me for our oldest son now, but it's impossible to explain that to a chronic taker. Regardless, I'll take back the $400 bucks she gives me per month. It's a start.
Unfortunately, her husband's income isn't so great and they bought a house that they can't afford without the $1200/month they were getting from me. They apparently expected it to last indefinitely (because they're dumb) and now my ex-wife is trying to make our oldest son feel guilty for putting her in a difficult financial situation by leaving her and moving into my house full time.

Also, our second son (15 years-old) has repeated issues with his step-father. Last week's episode ended when my son finally blew up on the guy and slammed him around their house after the guy got physically rough with him (again). Eventually, they both stormed out of the house. My son called me in tears and told me that he was walking to my house and asked if I could come pick him up.
He didn't want to go back to his mom's house. He understood that he shouldn't have lost his temper, but he just couldn't take it anymore.

Regardless, he had to go back.
He wanted to move in with me full time like his older brother. He's told me that repeatedly since last fall. He's actually told me that repeatedly for the last 10 years or so.

Unfortunately, he knows he can't because his mom can't financially support her new family without the income that his presence in their home generates. His mom has made that very clear to him for at least a decade.
I'd like to think that when a guy marries a woman with children that he'd assume SOME of the financial responsibility for those children, but that's not the way the law sees it.
In my crazy opinion, that should change. A 15 year-old American kid shouldn't have the pressure of financially supporting his mom and her children when there's a man in the house.