There is power in numbers, whether that power be for good and the benefit of societies, or whether that power is primarily for the selfish benefit of a few within society. Further to the point, corporations are created specifically to be successful for those that make up that corporation, by the use of capital and personnel in a manner that allows those corporations to become an economic force to be reckoned with. So that, corporations can be quite beneficial for society, in the sense that they are able to utilize economies of scale so as to ultimately produce products that typically sell for less than what was being sold before, as well as often being of higher quality and performance; in addition to also having the wherewithal and foresight to invest appropriate monies into research and development for future progress. This signifies that the grouping of people and capital into one corporation, allows that corporation to be far more powerful, then if such a grouping did not exist, for sole entrepreneurs are limited to just their own skill-set, and those that are not able to readily draw upon additional needed capital -- limits their ability to both grow and to take risk, by virtue of the lack of monies so needed to accomplish that.
So too, this means for many Americans, that when it comes to their own employment, that they are often restricted to finding employment with some entity that is offering such employment, as opposed to being able to somehow be gainfully self-employed, which thereby means that when it comes to their employment and thereby their wages, hours, and benefits, therewith, such is primarily determined with little of their input or say by the corporation so considering their hiring, unless they are part of a trade union, relevant to that employment.
In any company, the labor cost within that corporation, is a very important component in regards to that company's overall profit, gross margins, and even sustainability; of which, most corporations, would prefer to be in the catbird's seat when it comes to the setting of the prevailing wages and benefits therewith, not necessarily because they are greedy and evil, but often for practical reasons, such as budgetary concerns and future projections. This thus signifies that corporations prefer to be in the position in which those seeking employment with them, have to individually "negotiate" with the corporation, or to basically accept whatever the prevailing wage is, based on experience and economic conditions, that said corporation is offering. While there is something to be said, about a given individual having the flexibility to seek employment elsewhere, or to do research as to what is a fair wage within their locale and in consideration of their skills, the bottom line, is that one individual against one corporation is never going to be a fair match.
In short, this meant that individuals seeking employment were cognizant decades upon decades ago, that individuals and capital joining together so as to make one powerful corporation, meant that they too, in order to have any hope of any wage power as well as employment protection, needed to also join together into creating trade unions, so that they would therefore be formed into one body politic, and be able to receive a fair wage and fair employment conditions. Yet, today, trade unions in the private sector have been and continue to be in a very steep numerical decline, which clearly signifies, that present day government has vacated its role to be of assistance and of aid to the common man, but rather has thrown their lot completely in with corporate power, and thereby enriching the few at the expense of the many.