In the 80s, I worked in the Chicago area, which is very highly unionized. I worked with a company which installed very specialized home automation equipment in expensive homes. I found the unions to be very accepting of our situation. We had a job to do, and they had nobody that was specialized in that area. After being approached by the union boss, and explaining what we were doing, they allowed us to pull wire and do other work on the job sites, with no interference or complaints.
On the other hand, when we tried to set up our exhibit in McCormick Center at the trade show, the unions wouldn't let us carry our small display into the building and charged us $125 to carry a suitcase up the stairs to our booth. Then, they got somebody from the electrician's union to come and plug in the mains cord, and charged us another $125 to plug in the cord. When we complained to the show promoters, we were told that if we didn't comply we couldn't exhibit, or the union would shut down the trade show. We never went to another show at McCormick Center.
Unions can be good or bad.