Communism is not better than Capitalism in theory. In theory, both are wonderful systems that produce utopian outcomes. In practice we know this not to be the case.
Raw, undiluted capitalism doesn't really work very well, as there are too many imperfections in the market which people tend to exploit to everyone elses' detriment (ie. the 2008 financial crisis that fundamentally stemmed from a lack of Government regulation in financial markets).
Attempts at Communism haven't proven particularly effective either for a number of reasons (human greed, corruption, lack of an effective price mechanism on which to base the monetary system, poor central planning etc.). The main problem with Communism, besides the fact that evil ****s have tended to be in charge of communist systems, is that it's so unwieldy. It's hugely difficult for a Government to effectively organise the lives of millions and millions of people, and they always tend to get it drastically wrong, leading to poor outcomes for their citizens even when their intentions aren't bad.
A capitalist system with moderately socialist tendencies is the best current system. Key pieces of social infrastructure, such as education and healthcare are best managed by the Government, as this leads to better outcomes for society as a whole. But even then its not that straight forward. While the profit motive in the American healthcare system is the reason why America has the highest health care costs in the world, it has also led to the development of some spectacular new medical technologies, which benefit everyone, including those in socialised healthcare systems.
What's more, what may be great for some countries won't be for others. A heavily socialist country can often be extremely desirable for a developing nation which needs major investments in public infrasture and local industries in order to raise living standards to a level that doesn't involve immense human suffering. However for a developed, western country, a similar system can (and has) cause growth to stagnate and debt to mount. And there are an enormous number of other factors in play too that I really can't be arsed going into right now.
So while you can go around and round in circles arguing about which extreme end of the scale is worst, it's somewhere (not easily defined) in the centre of the economic spectrum where people do best.