I think you are confusing Darwinism with Social Darwinism. Many people make this mistake but social darwinism is bastardized version of Darwin's observations and theory that species change over time to adapt their environment. Darwin never agreed with Social Darwinism.
There is areas for capitalism to be corrupted and there is even more areas for other economic systems to be corrupted. Other forms of economies are also much more authoritarian in nature so I would never want to live under a different system because I believe in liberty, which includes economic liberty.
I do agree that we are debt slaves. The article illustrates how debt slavery as controlled by a criminal cartel has replaced outright chattel slavery and in that way you are correct.
I blame nobody but the people. If I tell you a lie it's YOUR fault if you believe it.