Many unions do nothing. When I was a printer in Kalifornia many years ago I was forced to join the union and pay dues. I asked the union rep what the union could do to protect me from firing and such. He said, “Nothing.” Seriously. The union had no ability to protect an employee or negotiate pay. A complete criminal fraud.
Yes, unions in theory may seem like a sensible thing, but in practice, they are usually just legalized extortion rings.