If people want to better negotiate their salaries, they have to unionize. Everything else is just unproven, speculative, untested pitter patter.
I live in france and all big enough companies are mandated to have union, doesn't mean that they help with salaries.
Those normally negotiate the banding and the COL increases and also know what the rates are.
Unions in the entertainment industries do :-) underpay or stiff workers and you get put on the "call first list" this is the PC name for another type of list.