It is, and they are. It’s why Reagan fired ATC strikers and blackballed them. It’s why private enterprise stockpiled machine guns and chemical weapons against strikers back in the Gilded Age. It’s why companies will spend billions to block Unions rather than just give workers the few million or so more they need over a decade to just maintain a standard of living. It’s why they’ll close down stores, warehouses, offshore jobs and outsource to contractors to penalize Unions.
Unions are a direct response to the inequality of Capital allocation and distribution.
Could MS replace them all with scabs? Sure, with enough time and money. But it wouldn't happen overnight, and things would get very dire if not company ruining in the meantime.