Hourly wages in Germany are not that different from the US. Depends a bit on how exactly to compare - nominal, PPP, net/gross, etc.: e.g., average nominal is about 10% higher in the US, real median is higher in Germnay, ...
Overlooking that we are comparing the richest EU state to all 50 US states, doesn't that further the point that having unions is are at best uninfluential.