I don't know about "developed."
I think there are still many discrepancies and legal loopholes. Unions can help but in private companies it is a different matter, for example. Owners pay and promote how they see fit, and every woman who is mistreated isn't going to go to court; who can afford the legal expenses! And if a woman is trying to get her foot in the door in a certain industry, for instance, she is likely to suffer the lower wages for the bigger picture hopes. Even though that can backfire.
Fashion: Don’t you recognize me? Death: You should know that I don’t see very well and I can’t wear glasses. Fashion: I’m Fashion, your sister. Death: My sister? Fashion: Yes. You and I together keep undoing and changing things down here on earth although you go about it in one way and I another. Giacomo Leopardi, “Dialogue Between Fashion and Death.”abridged