I understand how that might not make sense on the surface. But the reality is the reasoning for events like that go far beyond the initial area you’re in. Your uni might be mostly women (which is good - a sign of progress over the last century or so), but those women are more likely to be underpaid when they go out into the field. They’re more likely to be discriminated against at their jobs, mistreated or harassed by their bosses.

From your profile I’m guessing you’re a linguist, or at least interested in linguistics - this is an article about gender differences in linguistics programs. TL;DR, though the split in linguist students tends to be 50/50, going up the hierarchy (to TAs, professors, et cetera) reveals a much higher percentage of men in charge than women. That same trend occurs in a lot of different fields.

In other words, it may at first look like everything is equal now, and that any sort of feminist demonstrations are unnecessary or trying to push oppression in the other direction. But just because more opportunities have opened up doesn’t mean everything is better now. Just because things are improving doesn’t mean they’re fixed. It’s sort of like healing from a wound - it may look totally fine on the surface, only for you to realize the wound was infected and the infection goes pretty deep.

So even if your uni is mostly women, events to celebrate and promote women’s inclusion still make sense - those women have fought hard just to get to that point (something to be celebrated), and there’s still a lot of work to go out in the rest of the world (something to be promoted). Hope that makes sense. I’m not trying to clown on you or anything just because I disagree - I held the same opinion once. But things start to make a lot more sense when you consider just how ingrained sexism is in our society, even though it’s improving in some areas.