If I were in a union, I don't need them to negotiate on pay at all -- I'd want them to negotiate for better transparency about the ways that people get managed

If I were in a union, I don't need them to negotiate on pay at all -- I'd want them to negotiate for better transparency about the ways that people get managed out / fired, because at the company where I work, that's all very The Pit And The Pendulum, hanging over your head even if you're doing good work. I'd want them to set some boundaries around oncall shifts, because unfairness or imbalance in those practices is handled entirely through watching for attrition. I'd want them to approximate some portion of the protections that the employees in Europe that I work with have, because clearly that's not so unreasonable that the company would fold, and it's led to some really unfair situations being shoved on non EU teams. I find this kind of thing tiresome to have to get political about and my interests are simple enough to have someone else represent them.