Part of my reluctance is that I don't like big crowds. Part of it is I don't like to travel on Saturdays (the Sabbath)—I head for a nap not a hike on Saturday afternoons. Part of it is that's hours I could be calling my congresspeople, finding a way to gift subscriptions of Teen Vogue to libraries & schools in conservative areas, planning a women's self-defense seminar, & helping social justice organizations be clear about their aims & plans.
Can the march hurt? Probably not. Can it help? Did the 1963 March on Washington help? Yes, it seems it did. An article in The Week lists its 4 main accomplishments as creating momentum for the Civil Rights Act, making racism uncool, sparking the career of the NFL's first black quarterback, and saving the civil rights movement.
If we can fortify people's determination to live justly & reject intolerance, it will be worth it.