Or deluded and capitalist and claiming it's possible for companies to grow by 10% every year forever ...
You're laboring under a number of misconceptions. What those misconceptions are depends strongly by what you meant when you said the above. For example, I don't believe anyone has claimed that it's possible for companies to grow 10% every year forever. Let's assume, however, that you merely meant that proponents of capitalism claim that growth is better with capitalism than it is with socialism, and that the rest was hyperbole. (I compare it to socialism because that appears to be what you were responding to in 0123456's post.) If so, then capitalism's proponents are right to make that claim. Heritage Foundation makes an annual survey of the economic freedom of the various nations. Insofar as you can claim that economic freedom equates to capitalism (not too great a stretch, I hope), then following the link will show their finding that increasing capitalism correlates with increasing GDP per capita, with increasing economic growth, with reduced poverty intensity, with greater health, with greater education, and with a better environment.
As a lesser matter, I should mention that you're equating companies with capitalism, whereas capitalism can exist in the complete absence of companies. Wikipedia has this to say about capitalism: "Capitalism is an economic system in which trade, industry, and the means of production are largely or entirely privately owned and operated for profit. Central characteristics of capitalism include private property, capital accumulation, wage labour and, in some situations, competitive markets. In a capitalist economy, the parties to a transaction typically determine the prices at which they exchange assets, goods, and services." Notice the complete lack of the word "companies" or with its concept. I'm not saying that capitalisms can't have companies. Rather I'm saying that it's an independent concept. In fact, if you consider a continuum from economic freedom to a command economy, then companies are a step in the direction of command economies. Companies are a way to limit the risks taken by one party to a transaction (typically the seller) by increasing the risk to society. This is frequently called "socializing the risks," and for good reason.
or that somehow giving tax breaks to the wealthy and corporations makes everyone else's lives better ...
It depends strongly on the tax break. If you tax profits at the rate of 91%, then you eliminate many more business opportunities than you would if you taxed them at 27%. To give you an example, suppose that a particular opportunity costs $100,000 to risk. Perhaps a new pick-and-place machine for a surface mount printed circuit board line. Suppose further that the opportunity has a 50% chance of profiting $500,000 if it's successful, and a 50% chance of losing the entire $100,000. At 91% tax you have a 50% chance of losing $100,000, and a 50% chance of gaining (1-0.91)$500,000 = $45,000, for an expected loss of $5,000. You shouldn't take the risk. However, at 27% tax you have a 50% chance of losing $100,000, and a 50% chance of gaining (1-0.27)$500,000 = $365,000, for an expected gain of $315,000. Any risk with an expected loss shouldn't be undertaken, which means society doesn't benefit from the undertaking of that risk, offset somewhat by the possibility of the loss of the pick-and-place machine in a losing venture.
On the other hand, any number of other tax breaks, such as giving a guaranteed loan to someone that can't otherwise convince venture capitalists to invest, you would be right about.
Sorry, but in its current incarnation capitalism relies on just as much delusional fantasy and bullshit as communism ever did.
I'm not sure why we've changed the topic from socialism to communism, but...economic freedom seems to have a number of tangible, favorable outcomes as shown in Heritage Foundation's survey.
And it might surprise you that many countries have struck a nice balance between having private industry and pretending like you can have a functioning society if nobody pays for it.
Very few people advocate a pure capitalism. In fact, it would surprise me greatly if 0123456 weren't in favor of socializing national defense. On the other hand, it appears as though most countries could make drastic movements in the direction of economic freedom and still have a nice balance as measured by increasing GDP per capita, economic growth, reduced poverty, health, education, and environment.
But keep making it into your idiotic partisan position, and keep on demonstrating you're an idiot.
I understand that ridiculing your discussion partner and calling him names is an excellent technique to demonstrate your superiority, but I think I'll refrain for the present.