But, the major part of Marx's writing is about the dynamics of capitalism and its effect on our lives.
Profit is the driving force.
The needs of humanity, and the needs of all life are subordinate to the bottom line. He showed that capitalism has a never ending appetite that grows at an increasing pace. As it gained ascendancy in the world, everything would be turned into a commodity. He showed how the introduction of new machinery and labor saving methods by one capitalist would require industry-wide imitation by others and result in ever increasing unemployment. He explained the process by which wealth would concentrate into the hands of a few, and how small capitalists and independent producers would lose their property and fall into the ranks of the working class.