It is nice to feel a sense of community and support, but beyond that, I don't know what the march accomplishes.
I have zero expectation that Cheeto gives a flying you-know-what about women's marches.
There are so many well-intended advocacy efforts done improperly that result in no or negative impact. This is especially true when there are strong emotions and lack of professional guidance. We see this a lot in the ex-jw world.
I was tempted to go, and tried to find out about the event and its aim. The website (for my city's march) had 2 vague sentences about its purpose, which was basically, "Stand up for your rights."
Advocacy without a good strategy is just venting your feelings. I can do that at the corner bar.