Unions can be what the workers want them to be. The industrial time-in-role thing can be a reasonable match to industrial industrial jobs. But collective bargaining can include performance-based pay. E.g., the union negotiates the overall base raise and the size of the performance-based raise pool, and then managers decide on raises and promotions. They can also help you resolve situations of individual managerial unfairness, something that HR is supposed to do but is very rarely effective at.