As a former member of a union, I honestly find it odd at how many people think that unions are always good. Of the two unions I was a part of and watching what my dad went through with his Union I'm actually fairly anti-union at this point in my life. I watched a guy get fired for sexual harassment, and rehired due to pressure from the Union. I watched my father not get a manager position, because of seniority ruling…
Unions are made of people, like any group, there are as good or as bad as the people they are made of. Unions absolutely can make the difference for underpaid workers. Unions have lawyers workers can get advisce from and they level the playing field between the employer and the worker.
What I find odd is you pretending a lot of people think that unions are always good. In US the majority of people think unions are bad.