I think the real issue here is: the police want to show that without them, things turn to chaos. Instead, they show that with them, things turn to chaos. Meanwhile, the protesters want to show that without the police, things are peaceful, and they seem to be succeeding.
That's not a great story for people who believe in police brutality, of course.
And yes, if the entire police department believes that they need to use force to dominate the American people, they refuse to stop when ordered to by the civilian government, and resist change, then disbanding the police and starting over with a better organised police force might not be such a bad idea at all.
It's not easy, and it's important to quickly have some alternative to fall back on, but when it's the police itself that's part of the problem, something needs to be done about that.