*I think it's a primal instinct for females to seek a breeding partner with high earning potential
Sorry, but I think that's the vilest reason for choosing a "breeding partner" [ugh!] ever. And in that scenario, more fool the breeder for going along with it*
Unpalatable perhaps but not untrue. Few women, when seeking a man to settle down and start a family with, seek a man who is unemployed or earning minimum wage. On a practical level it means a lower standard of living, less choices in life, less resources for raising children.
For a lot of women, power is sexy. And power goes hand in hand with wealth, giving a man higher social status than his lower earning peers. However much we try to dress it up, powerful, high earning men are generally viewed as more attractive than low earners with low social status.
I remember reading a study about how women show a preference for men with high testosterone when ovulating, yet have no preference the rest of the month. The women consistently preferred the men with high testosterone during their fertile period. It doesn't make sense in modern society yet evolution hasn't stamped it out yet.
I don't think we should dismiss the idea that many females prefer high status, resourceful males who can give children a better start in life. It's not 'fair' or particularly nice but it's true for most of the animal kingdom, and humans are not so different.