Hollywood actors, writers and directors all have unions. Professional baseball and football players have unions.

You really think any of those people feel like they don't have the opportunity to stand out? Or that their financial upside is too limited?

Don't generalize about what a union can be based on what unions for one particular type of workers are. When a group of workers' labor is easily replaceable, of course their union is going to focus on things like uniform pay -- that way the workers won't get trapped into a downward spiral by demands that they undercut each others' wages or lose their jobs. But unions for workers who aren't easily replaceable will have different priorities.