For What
18 He will give back the fruit of his toil and will not swallow it down; from the profit of his trading he will get no enjoyment. 19 For he has crushed and abandoned the poor; he has seized a house that he did not build.
Job 20:18-19 ESV
In these verses Job's friend Zophar describes a consequence of taking advantage of the poor to accumulate wealth; which is the inability to enjoy it. Many people have money in this world, but have no joy. Many people think that more money can buy them more happiness, and find out that they are still unhappy. Many are willing to do all sorts of things that they know they shouldn't do to get more money, and discover that it wasn't worth it. It's because money is a poor substitute for meaningful relationships, and Jesus Christ.
We should not expect to be able to mistreat people for material gain, and get away with it. How we make money and obtain possessions matters to God.