Don't unions work best in fields where quality is very uniform and expertise counts for very little? I'm thinking about low skilled jobs that can be mastered in months or years. Unions create salary progression, and benefits for seniority where there is otherwise no reason for them to exist. When no one does anything better than anyone else, it makes sense to negotiate as a block, individuals have no power.
Now compare that to tech where the 80/20 rule is patently obvious to anyone in the field. The best engineers are worth literally 10x the worst engineers, but often get paid only 2-3x as much. 20% of the field, with 80% of the negotiating power, wants employers to find better and better ways to pay proportional to value-add, not to increase the floor salary, or working conditions across the board.
Now compare that to tech where the 80/20 rule is patently obvious to anyone in the field. The best engineers are worth literally 10x the worst engineers, but often get paid only 2-3x as much. 20% of the field, with 80% of the negotiating power, wants employers to find better and better ways to pay proportional to value-add, not to increase the floor salary, or working conditions across the board.