When a union is at the bargaining table where does their power come from? Does their power come from who they send to negotiate?
Part of the decline in union power has been the idea that union leadership, who they are and their abilities to negotiate, is what wins good contracts. This idea justifies inflated salaries which then leads to union leadership living in a class above the rank amd file members they should represent. This entire concept is referred to as business unionism.
The truth is the power of the union at the negotiating table is their ability to withhold their labor. The rank and file members hold the power, the elected leader is just a representative. Closed door negotiating delegitimizes the true power of the union which is why business owners have sold you the concept that it delegitimizes the negotiations.