Guaranteeing people advancement and pay improvements over time tends to make everyone at least a little happy. It means a future you can plan around for everyon

Guaranteeing people advancement and pay improvements over time tends to make everyone at least a little happy. It means a future you can plan around for everyone. For union leadership, this has the great perk of more or less aligning incentives among members. This works as long as a sizable chunk of members don't start to see themselves as equipped to do significantly better than their supposed-peer. And, well, as soon as you do performance pay it means someone's going to lose out, because now workers are competing with each other. And this definitely aligns incentives away from where the union leadership wants them.