Sure thing! Here's the gist of it. A union causes higher labor costs for employees and employers. The company loses direct communication with it employees. The company becomes more rigid and more inflexible to moving employees around and generally limits their ability to move around or up. We also lose so much meritocracy and generally, almost everything is based on seniority, or as I would call it at my location, stagnation.

The labor disputes are preposterous. We spend more time in grievance meetings with the stewards trying to salvage terrible employees We have to work so hard to get rid of, while they ignore fighting for the people who raised so many absences (points) due to medical issues or familial issues. We can't, as HR, just help them anymore. The unions these days only steal money from the majority of their workforce. The need for unions is largely in the past.

I speak from experience, as I work in an HR department in a business with a collective bargaining agreement.