I spent too many years trying to get work accomplished on large union construction projects. It was a lose/lose arrangement; cost/schedule overages, shoddy work, sabotage, and some good workers being prevented from doing good work.

I do think that unions had a place in the US during the early 20th century. They caused many labor law reforms that were needed at the time; that time is over in the US. FWIW, I think unions could serve a similar function in the developing world today.