Unions only work when union leadership is actually working for the betterment of the entire unit, rather than personal clout. I was in a union that ran well, protected employees, and had a great working relationship with management. Issues were handled efficiently and effectively with the contract in place. Then union leadership changed because a retiree rallied to become president, and the effective president stopped trying so hard because of it. So leadership changed and that union went downhill. Current leadership handles issues so poorly, nothing gets resolved and raises are not going to be as high as they could have been negotiated too. The current leadership values the provided lunches at the negotiation meetings over discussion of the actual topics, and working together to come to an agreement for everyone.
Another union I was a part of prior to that was for a big box wholesale store. I was sexually harassed in front of customers by another union member. The meetings were facilitated by management and the union. Management had my side on the issue, but the union advocated for the harasser due to years of service and seniority. They couldn’t even guarantee I wouldn’t work with him again. I eventually left that job, for multiple reasons, but a big one was that experience really broke me. I never felt comfortable working around that person and knowing that my voice would always be lesser compared to anyone who had just worked there longer.