Without unions, without government intervention and with large supply of labor the wages will stabilize at the subsistence level.
In free market context the wages are seen as the cost/expense/necessary evil so the market optimization will bring them to the minimum.
Well, unions have a function, unless you believe the old "sancity of Contract." myth. MY complaint is that Union leaders use dues money--lots of it-- for purposes that have little to do with collective bargaining. When the union leaders dress as well as the bosses and live in the same part of town, one might surmise that they are skimming for their own purposes. When the union gives all of its money to one political party, even though 40% of its membership votes for the other, one surmises that they are more interested in political power than in their members. Hell, business gives money to both sides. If you want to influence politicians, you better cover all bases.