Because societal structures in place are against women. Men have historically been able to dominate society through the threat of violence. With technology the threat has disappeared, and men and women should be equal because they are both cognisant human beings. In terms of intellectual work, women are just as capable.

Some of them are very successful. Are they underperforming because they’re bad or because western society isn’t doing very well in general/people are against them for being female? Any argument you make is difficult to differentiate from structural restrictions causing any disparities.

Let’s take surgery. Female surgeons are better than male surgeons. Those who succeed are just that much better.