Oh boy... lots wrong with what you said, so a bit to unpack here.
Lenin was absolutely inspired by Marx. Mussolini was while he was a syndicalist and a member of the Socialist Party of Italy, but would renounce class struggle in favor of class collaboration, which was an endorsement of corporatism, so he walked back on his prior socialist beliefs. Hitler on the other hand did not believe in Marxism at any point in his life. He had no converting to do. Leftists were resisting nationalism for the most part while he made it his identity. Even as Chancellor, he made it clear that "National Socialism" was not "Marxian socialism". For sure, it had everything to do with racial hierarchy, and nothing to do with worker-owned means of production.
Marx alone is not terrible, and should not be completely written off. Leninism is what introduced vanguardism, democratic centralism and resulted in totalitarianism. Marx has inspired generations of socialists and working class people. His critique of capitalism is one of the best, and many of his predictions were significant, many of the things he said were ahead of his time and there is much to learn from him. That said, there are things we shouldn't take from him. A "dictatorship of the proletariat" being the biggest one. Most anarchists are not Marxists, but many draw inspiration from Marx, and still insist on decentralization and oppose authoritarianism.
Alexander Berkman said anarcho-communism is truly voluntary communism. Even the anarchists in Spain amid the Civil War were careful to ensure collectivization was voluntary, and not repeat the same mistakes as Russia. All anarchist communists reject the idea that any laws or central authority would be necessary after the liberation from capitalism.
Individualism is unfortunate because their system still believes in markets and a strange concept of property. They also think violent revolution is just as bad as the abuses of the state (which is why individualists have never had any success). In reality, markets should be abandoned, money should be abandoned and no fictitious authority should govern whether someone eats, has shelter or has access to water or not. We operate best when we cooperate, and hold things in common.