A lot of myths in this article as well.
No well run business will pay workers what they are worth, they want to make a profit or why bother. They pay what workers cost, as long as it is less than they are worth minus a profit.
Unions help raise the cost to the point of worth.
The reason relative wages have dropped is less to do with unions waning, and more to do with free trade and automation.
Free trade expanded the labor pool so the labor price dropped.
Automation reduced labor demand so the labor price dropped.
The government needs to raise the price of labor for the good of society, just like they raise the price of intellectual and real property. The only question is how much.