Unions have done a lot to help workers from being taken advantage of. Some good work rules to prevent an employer from telling a worker he has to do something, or if not, get fired instantly.
On the other hand
I have some cargo inside a port terminal. The empty container to be loaded is also inside the terminal. But the port is unionized......they won't load the container......so both the cargo and empty container have to be taken out of the terminal, loaded, and taken back to the same place at the terminal where they sat before.......added cost of $ 2,000.