Unions had their place - when this country had masses of largely unskilled and uneducated workers in production and manufacturing. Those days have been over for decades. Even then the unions were corrupt and lawless, so it could be easily argued that they never had their place. The unions most certainly never had a place in the public sector/government.
I agree they should not function in the public sector.
But they do help balance things in some cases. The problem is that the unions have gone full tilt Democrat over the years, and as a result totally corrupt.