I very much doubt that is the problem. Lots of people would be happy for their more productive colleagues to get more money, if anyone asked them.
It's much more often managers who don't want to have this type of employee, because they fear for their positions or other similar issues. In particular, this happens via the absurd practice of refusing to give significant raises year to year, forcing the best workers to leave for a new company, taking all of their hard earned organizational knowledge.
Not to mention, I'm not talking about collective bargaining for salaries. This is about an economy-level change, not a company level or even industry level change. And it would benefit the best workers just as much as the worst.