I think it’s a fair question/point. Different factions within feminism will give different answers to that. Personally as a cis man I am fine with feminism focusing primarily or exclusively on women’s issues (it’s in the name), we should have other movements to deal with the way those same issues affecting other genders. Activism and organizing is almost never a zero-sum game, someone can be a feminist and an LGBTQ activist and a socialist for example.
The way this ties into the OC is that it is OK for feminist activism to take away privileges from men if that means improving rights for women. Even if there was a dichotomy of “there are fewer hetero relationships but women are safer from sexual harassment” as presented by OC — which, to be clear, is a false dichotomy and not actually what the vast majority of feminists are advocating for — it would be a fine step to take.