Hygro
soundcloud.com/hygro/
There is no such thing as an economic system, let alone an economic system that has failed. All economics are transactions between people. Failures and successes in the economy happen form day to day, as people simply make mistakes. Sometimes, such are larger than normal, but the basic idea is the same.
The reason we do not Communism is because we have a fairly acute sense of scarcity, which may or may not be justified. Capitalism was made possible because religious prohibtions on lending were gradually relaxed and property rights were forcibly simplified through government intervention (i.e. land enclosure). I wouldn't say other systems of economics failed, rather, political choices that favoured centralisation and secularism (leading to the end on the taboo on lending) led to the advent of capitalism.
While economic systems by definition exist, I'm glad when I see people understanding capitalism as something other than an economic system.