Also Anarcho-Communism is an oxymoron.
Anarchy is a derivative of An Archos which means NO RULERS.
If the only way something can be achieved is by FORCE then there are those imposing their rules. You have rulers.
Communism on a small scale such as a commune can actually work. It does not scale well and when done at a large scale it is the opposite of anarchy. It is often one of the worst forms of authoritarianism.
If 1 person wants to tell you what to do and you don't voluntarily want to do it, it does not suddenly become REQUIRED because 10, 100, 1000, or X amount of people want to force you. Communism at a large scale does not lack rulers... it simply turns the mob into rulers. Though in reality that mob doesn't end up controlling it. It still ends up with it's oligarchs, and in some cases plutocrats at the top directing it.
It becomes the government, the RULERS. By its nature of how it deems property and lack of private property it soon becomes the ultimate form of monopoly as well.
I don't need to back this up. It's been tried many times, as well as it's stepping stone Socialism, and the results tend to be the same.
As to Capitalism. That depends. If what you see today you call capitalism then to be clear I call that Cronyism.
To me the true capitalism is synonymous with free market.
As soon as a government or ruler can start dictating the rules of the market (you cannot buy from them, you must sell the same, you cannot operate here, you cannot operate there, etc) then it is no longer a free market. And when those who make these rules can support their "friends" and block "others" it becomes cronyism. Yet capital is still exchanged... so is it a form a capitalism... sure. Yet capitalism exists within Socialist countries too it is just heavily manipulated. Capital is still exchanged. It also exists within communism. The rules of how it can be exchanged are just "different", or at least they seem to be on the surface. When it comes to those who rule it doesn't seem so much different, just easier for them to steal from everyone else.... wait they can't steal as there is no private property. Which explains why they live SO much better than the other citizens.
The interesting thing about cronyism (essentially the rulers giving their buddies advantages, and blocking others) works just as well in communism, socialism, and perhaps even better in some cases. It also doesn't require MONEY/CAPITAL to exist. All it needs is an exchange of power in whatever form it comes in.
The "free market" is a trope. It's held out as a kind of ideal, but it's not likely to ever come to be.
Just look at the history of modern capitalism. It was founded via cronyism, through these trading companies that basically helped establish imperialism. These trading companies were chartered by monarchs, and did their business supplying smaller businesses.
Check out the history of the East India Company. https://www.britannica.com/topic/East-India-Company
That's early capitalism.
Capitalism is cronyism.
It has always been cronyism. It's also always been racist. It's also always been imperialist and sought to take over other countries for some European country that financed them.