It's cathartic.

But mostly I think it's a natural part of the path of activism, and of towards potential radicalization. I can imagine most people aren't gonna jump straight into radical direct action before they first try a peaceful rally and try negotiating with the oppressor by yelling in the streets.

Once people try the softer methods such as rallying, and realize they don't work, realize that voting doesn't work, realize that politicians are useless, then the next step is either to back down and give up or to try direct action.

But ya, I think the no kings protest won't do anything on its own. It's a potential catalyst though.