All attempts to implement it have also resulted in the creation of new elites that have ruled in their own interests rather than of the community.
Say what you will about the nomenklatura, their material privileges pale in comparison with the privileges of the elites in a capitalist system.
An ideology that values equality restricts the amount of looting that the social elite can do for themselves.
The "failures of communism" can be explained with the chaotic circumstances and external pressures that favored its implementation as militarized/police states. Which, ultimately, the capitalist states also are when you really look at it. Who has more prisoners per capita, China or the US? Discounting the stalinist era, who had more prisoners per capita, the USSR or the US? And what is prison in either side but the to to enforce social control? For this comparison a thief in a capitalist system can be considered a political prisoner if his offense was against property rights that communist countries didn't recognize at all (everything "intellectual property, to start with), or a criminal out of necessity or desires encouraged (consumer advertisement that is more intense than any communist propaganda manager to be) but impossible to satisfy.
We have more data points for Marxist failure than we have for the failures of fascism, and body counts to match. There isn't a meaningful distinction between someone claiming to be a Marxist vs fascist in terms of the suffering advocated.
No you don't. But that's besides the point. Body counts in the many wars and disasters we could discuss were results of specific circumstances, actions of governments guided by these ideologies. But they're not inherent to either. The most you can change them with inherent deadly features is that fascism called for nation expansion through war, and marxism for revolution leading to social changes, and both can be anticipated to cause fighting and deaths.
The real failures of communist regimes were the rise of leaders whose main agenda included the aggrandizement of their own personal power and suppression of the democratic aspect that is part of marxism. Stalin's and Mao's accumulation of power are examples o what to avoid. But they were not features of the system, they were problems that can befall any one. King Leopold's capitalist rule of Congo, though his own
company, was an even worse atrocity. Are the ones condemning communism because of Stalin and Mao also condemning capitalism as a failure because of Leopold's genocide in the Congo? If not, then you're being hypocrites. Where it comes to abuse of power there are ample other examples to paint any political regime ever tried as deadly. That's not to way to compare them. That's a distraction to derail attempts at serious comparisons.
I think Marx would laugh at the idea of "marxism", but I'll use the term for convenience. Marxism's idea (Marx's idea in his political activity) is, going to the bare basics, quite simple: material conditions matter and in capitalist societies the ownership of the means of production gives its holders economic and political power over their workers. This in turn leads to resentment and pushback by the workers: class conflict. In fact marxism does not
call for this conflict, it stresses that
the conflict already exists. What marxism does is propose a solution: the workers should aim to take over and socialize the means of production, thus ending the separate class of owners and so the class struggle between the two. How best to do it has been a subject of fierce discussions for more than a century now. I think anyone with good sense will agree that how to change a situation depends on the present situation, there is no universal recipe. Attempts to devise and spread one were a cause of several disasters...
In capitalism vs marxism discussions (those untainted by derailments about who acting in the name of one or the other killed more people) the strongest defense of capitalism is not that it is "more free", or "more effective", but that it will arise again where it was once buried. As in, greed is a recurring human feature. The strongest promise of marxism was the opposite: that communism is is the next (and hopefully final) stage of human social evolution, where a popular shared control of all the basics of life enable people to be free, the idea of ruling each other obsoleted and not really a thing people in a society of abundance want to waste their lives with.
And socialism (which predates the specific marxist analysis of capitalism) has indeed advanced at least part of that promise already: democracy as we have it today, universal suffrage, was something socialists, marxists and communists fought for. Later the leninist communist variant of organizing the political structures of the state around those of a party divorced from it, wanting a single party and "democracy within the party only", with the results we know. But others did not. History goes on. Whether or not to
some end, I'm certain it won't be us to discover in out lifetimes. But we can hope to implore what we live with. These are not obsolete ideological discussions, they continue to be very relevant.