A key difference between men and women has always been why they form relationships. Women traditionally engage in hypergamy because men have more assets relative to women, and women need assets for raising children, improving their lifestyle, etc. Whereas men don't look to women for assets, but for companionship to improve their lifestyle. Guys' main focus is someone they can enjoy spending time with and who they can have regular sex with. What's changed since WW2 is women have gradually accrued more assets and the ability to earn more. Ignore the whining about the supposed wage gap. Today, men and women doing the same job with comparable experience earn the same. Indeed, single never married never had kids women have been out earning single never married never had kids men for 50 years now, but no one seems to be concerned about that wage gap which is actually larger.
So women don't need men as much as they traditionally did and won't settle for what their mothers or grandmothers would have. If they're unhappy in a relationship they will on average withhold sex to some degree. Whereas men still don't generally consider women's income as a primary factor when choosing a mate until you get to higher income levels where you have a lot of rich marrying rich. Men still prioritize having an active sex life and assume that their role is to earn money for the family. At regular incomes though, divorce is much more common even though it is relatively far more costly. Because of laws regarding alimony and child custody, women initiate divorce twice as often as men. One suspects men would initiate divorce a lot more if they didn't have to pay for it as much given that what men are mostly looking for is a partner they enjoy being with. Since it's so costly to split up, they save money and try and satisfy their urges through affairs or paid sex instead. Although depending on which study you look at, women have affairs as much as men do. I saw a study that claimed that the most common thing a woman will ask her partner after discovering he cheated is not "Do you love her?" But "Did you spend money on her?" Again, an assets issue where money equals love. Ironically, most men having affairs aren't looking to end the main relationship, they mostly want the attention they used to get. Whereas if a woman cheats, chances are far higher she is already considering a move. Indeed, when women end a relationship it is usually when hey have their next partner already lined up to smooth the transition. It is far more rare for men to dump their wives in order to shack up with their side piece.
One of the ironies of this hypergamy is that with women earning so much more now, fewer men have the higher incomes to make them desirable. So you have more women chasing a smaller elite set of men, and some of these men realize heir enhanced status and become players, further reducing the eligible pool even more. Women have not yet adjusted to dating down, which is what men have been doing for a long time. Indeed, the odds of divorce are 400% higher when a woman out earns her man than vice versa. Women making more tend to be very busy at their jobs and are "too tired" for sex afterwards, either genuinely or because they see their lesser income partner as less desirable. We've seen this play out in the black community in the US for decades now where black women have been out earning black men for various sociological reasons and absent fathers and single mom families are far more common. I know many successful single white women who don't even bother with dating for mating. They just pay to get fertilized and raise kids themselves / with paid or family help, no man required. How many men do you know who want to consciously conceive and raise kids on their own? The implications of all this are profound and hard to anticipate, but we do already have good evidence of worse outcomes for kids raised by single parents in general. Sure rich women can likely improve the odds for their kids but that's cold comfort for the kids without rich moms.