Most women are only interested in men who have a socioeconomic status that is equal to, or greater, than their own.
This made sense back when women had little economic power, but is counterproductive in modern times. As a result, there are a lot of 30+ women out there, complaining that there are "no men." Men, who don't have this hangup, are perfectly happy being with women who are "less successful," which is why you see tons of older men with younger women.
I think that the primary cause of the "gender pay gap," is the fact that women WANT men to make more than them. Most women don't want to be with a man who makes less. This creates a social pressure on men to be ambitious and careerist. But, feminists never talk about this.