Interesting that this would be the case in Europe. Germany has had 'codetermination' laws for decades, where they have (typically union) representation on the boards of large corporations[1].
This doesn't invalidate my remark though. Nothing says these union board members are there to make the company more competitive. They are there to provide better working conditions.
Still, the point stands that of all the European states, labor is arguably strongest in Germany, and at the same time Germany industry is extremely competitive. If strong labor was a huge competitive disadvantage you'd think Germany would be falling behind, but instead it's quite the opposite.
[1] https://en.wikipedia.org/wiki/Codetermination_in_Germany