No two people are identical, and the range of difference between the two most extreme men almost certainly exceeds the range of difference between the most woman-like men and the most man-like women. Given the obvious differences between humans, nobody expects that every single person will contribute identical value, or should be valued identically.
However, there is a very, very, very long history of the inverse. In nearly every area of life, the activities and contributions most commonly fulfilled by women are under-valued, while the activities and contributions most commonly fulfilled by men are over-valued. This can be seen historically, as the primary occupants of careers shifted from one sex to the other. The early computer programmers (women) were treated as doing secretarial work, while modern computer programmers (mostly men) are compensated like rock stars. Conversely, early school teachers were highly respected and well-compensated when they were mostly men, and respect and compensation both dropped relative to other careers as teachers became more likely to be women.
These are systemic biases so ingrained that we don't think about them. People are lining up to respond to this comment to helpfully explain to me that those earlier programmers weren't the same, or that modern teachers are every bit as respected and well-compensated as they should be, or whatever.
The Venn diagram of all men and all women is not a circle, because of course there are differences. But there is much overlap between the two circles, and women are mostly not valued equally where the circles overlap, and the non-overlapping areas of each circle are valued completely differently as well.
When you see it, it's clear as day. When you don't or won't, it sounds silly. Feel free to dig in to the truth of it, or dismiss it as folklore.