I believe that the existence of unions is necessary. Without any unions worker rights would degrade pretty significantly. I also strongly believe that unions aren't the right answer in most situations.
One example - teachers. In the public sector, teachers are unionized yet underpaid, and in general terms, have unfavorable work conditions.
In the private sector, teachers get paid much better and have the freedom to actually run their classroom in the way they see fit.
The union isn't the cause of this disparity, but it clearly doesn't overcome it.
>In the private sector, teachers get paid much better and have the freedom to actually run their classroom in the way they see fit.
While this might be true wherever you are from, it is definitely not universal. Every US state I have lived in has been the opposite.
At a private school, the advantages to teachers are the student base is self-selected and can be expelled, and the school can teach things a public school cannot (often religious).
At a public school, pay, benefits, and job protections are much better.
Being able to "run your classroom the way they see fit" is a school-by-school work culture thing, but a teacher with more job protections would always have more leeway in how they ran their classroom. A teacher working at-will could never truly run their classroom the way they saw fit, because "do X or you're fired" is always a possible ultimatum.
One example - teachers. In the public sector, teachers are unionized yet underpaid, and in general terms, have unfavorable work conditions.
In the private sector, teachers get paid much better and have the freedom to actually run their classroom in the way they see fit.
The union isn't the cause of this disparity, but it clearly doesn't overcome it.