The basics?
Feminism is the reason any progress in these areas has been made:
Women being able to make the choice to have sex, or not, and with whom, without being shamed or forced.
Women being able to do things in the world like make their own money (and therefore not be economically forced to get married),
Women being able to have their ideas and art not automatically dismissed (without pretending to be a man).
Women being able to have an influence on the world socially and politically.
Men and women being able to transgress traditional gender norms without facing unnecessary consequences in their communities.
And to the extent that those principles are still compromised, it continues to work for change in that direction.
Feminism is also a massive resource from a personal development standpoint, as its analysis provides an extra tool for critically examining the (often harmful) messages society gives us about sex and gender.
That's just the beginning too--there are all sorts of niche ways feminist analysis is helpful in PD.