If by Capitalism you mean the rich getting richer, then that is definitely working. But it's not working for us. The extreme concentration of wealth is not really a good thing for society.
I could just leave it at https://en.wikipedia.org/wiki/Strawman. After all, this is what most people who are talking about "capitalism" are doing: strawmanning it. I guess the problem is that many of us, neo-cons, neo-liberals, classical liberals, libertarians, anarcho-capitalists are trying to defend capitalism, but all we mean fairly different things.