My overall opinion on that matter is that, ultimately, Einstein grasped the logical necessity of Socialism as outlined in Why Socialism? but contained many chauvanistic attitudes common to Western Socialism. He changed his tune from being firmly anti-Soviet in the 20s to overall greatly complimenting Lenin:

“I honor Lenin as a man who completely sacrificed himself and devoted all his energy to the realization of social justice. I do not consider his methods practical, but one thing is certain: men of his type are the guardians and restorers of the conscience of humanity.”

The chauvanistic attitudes, however, are often swept under the rug. With respect to Chinese people, he commented in his diary:

“Chinese don’t sit on benches while eating but squat like Europeans do when they relieve themselves out in the leafy woods. All this occurs quietly and demurely. Even the children are spiritless and look obtuse… It would be a pity if these Chinese supplant all other races. For the likes of us the mere thought is unspeakably dreary.”

Overall, I believe he harbored extremely reactionary views, such as support of Zionism (which, while eventually fading, persisted), the shown racism towards Chinese people, and more. While the logical necessity of Socialism is elucidated quite clearly in Why Socialism? it appears he harbored western-supremacist views.

This stands in stark contrast to contemporary intellectuals like Frantz Fanon, who lived in Algeria and the USSR. I don’t think Einstein should be lionized, however I do think his essay Why Socialism? serves as a good starting point for those who think Socialism to be utter nonsense, and serve as a springboard for actual, genuine works of theory.

I think Parenti said it best, in Blackshirts and Reds:

During the cold war, the anticommunist ideological framework could transform any data about existing communist societies into hostile evidence. If the Soviets refused to negotiate a point, they were intransigent and belligerent; if they appeared willing to make concessions, this was but a skillful ploy to put us off our guard. By opposing arms limitations, they would have demonstrated their aggressive intent; but when in fact they supported most armament treaties, it was because they were mendacious and manipulative. If the churches in the USSR were empty, this demonstrated that religion was suppressed; but if the churches were full, this meant the people were rejecting the regime’s atheistic ideology. If the workers went on strike (as happened on infrequent occasions), this was evidence of their alienation from the collectivist system; if they didn’t go on strike, this was because they were intimidated and lacked freedom. A scarcity of consumer goods demonstrated the failure of the economic system; an improvement in consumer supplies meant only that the leaders were attempting to placate a restive population and so maintain a firmer hold over them.

If communists in the United States played an important role struggling for the rights of workers, the poor, African-Americans, women, and others, this was only their guileful way of gathering support among disfranchised groups and gaining power for themselves. How one gained power by fighting for the rights of powerless groups was never explained. What we are dealing with is a nonfalsifiable orthodoxy, so assiduously marketed by the ruling interests that it affected people across the entire political spectrum.

To that end, Marx’s conception of Socialism, that being a state run by the proletariat along the lines of a publicly owned and planned economy, has existed in many areas, and does to this day. These are called “AES” states. You’re partially correct in that no AES state has made it to the historical stage of Communism, which requires a global world government and a fully publicly owned and planned economy, but this is a historical stage requiring Socialism to be fully developed first.

I think you would gain a lot from reading some books on AES states, such as Soviet Democracy by Pat Sloan and Is the Red Flag Flying? Political Economy of the Soviet Union. These aren’t “oligarchies,” or whatnot, but Socialism in existence, warts and all. We need to learn from what worked and what didn’t to progress onwards, it’s clear that Capitalism is in a death spiral and Socialism remains the way forward.

In general, actually, Socialism has a better track record than Capitalism when it comes to “tyrants.” You should read Blackshirts and Reds.