This certainly seems to focus more on the male insecurity of making less than a woman does in the relationship. I believe this is not as much of an issue with younger generations than it is older. Older generations it is very much a matter of pride and self worth for a man.
In the age, I think economic differences do matter and are important. Potentially even relationship making or breaking. But the difference isn't in who makes how much, it is about the economic goals of the people in the relationship. Someone with long term goals hoping for an early retirement is going to have a lot of trouble with a live in the moment spendthrift that wants to vacation while they are young. Someone who wants to break out of debt is going to be challenged by someone who doesn't view being in debt as a bad thing.
When it comes to keeping a relationship together, being aligned on a financial future is far more important than which person is making the money. And if you are not aligned then the person making the money is going to get angry that you do not respect their contributions or the person making less is going to feel like they are not important and just along for the ride.
It's all about where you are going, not where you are at present.
