America is home to a significant amount of gargantuan multinational corporations, in which, some of these behemoths, actually get the majority of their profits not from domestic consumption and by those accompanying sales, but rather from foreign markets and foreign lands. That shouldn't be all that surprising, as the population of America is only about 4.4 percent of the world's population, and even though America is the wealthiest individual nation; in aggregate, the world has much more money than Americans do in total. So too, when it comes to labor, multinational corporations have made the conscious decision and, in fact, have set up legislation of all types that permits them to utilize overseas labor as well as to create overseas facilities, not because there is an absolute necessity that they do so; but for the most basic of reasons, which is to increase their profit, by lowering both their labor costs as well as their infrastructure costs, and thereby seamlessly increasing their profit.
As might be expected, the battle between those that have capital, who are often also those that are doing the employment of people that thereby involves the usage of that capital, is not ever a fair battle; especially when those that need employment are non-unionized, and without a lot of viable options, while also suffering from their fundamental need for employment of some sort in order to try to make some semblance of a living. That is the most salient reason, why labor is so cheap overseas, because those without capital and without the utilization or even the availability of the unionization of labor, are going to have to, more times than not, accept what is being offered by those that dictate those terms to them.
The attitude of so many multinationals is almost never to try to make a fair deal and to thereby pay a living wage to their overseas workers, especially in third world countries, whether they are directly employed or subcontracted to those multinationals; nor are these multinationals overly concerned about taking care of the environment in a responsible way; but rather these multinationals look at their overseas operations, as simply a numbers game, and wherever they can cut costs, or cut a favorable deal, and thereby add to their profit, that is what they often do.
Quite clearly, multinationals exploit overseas labor and legislative laws in a manner that favors them, so that they can thereby reap their profitable rewards for having done so. While it is true, that multinationals do provide employment; the typical conditions of that employment, overseas, including safety, work hours, healthcare, as well as compensation, are in comparison to what is required from them for those that perform similar work in the United States, rather paltry.
So then, quite simply, multinationals utilize foreign labor and foreign facilities, mainly because they can pay those workers a heck of a lot less money, and further often do not have to overly worry about labor laws, environmental laws, or pretty much any law of substance, because their power within those foreign lands is supreme; for they have capital, and the promise of employment, though the end result for the average foreign worker is pretty much sheer drudgery while also having their dreams of meaningful success, crushed.