They don't need the force of government because over time they have become an active force of government; an essential part of it, and by the looks of the violence that goes unchecked, the shock troops of the Federal government.
So no, they don't have to be beneficial to "working people." Assuming you accept the myth that unions create "kinder, gentler, competent and dedicated" workers.
I wonder how the government provides their "uniforms." Through a Soros-funded NGO?
WHY IS THERE NO POLICE PRESENCE?
Have the police unions passively joined the thugs via their absence?
What's going on there?