Those were all “socialist” by self-titleing only.
Socialism, by definition, puts control and ownership of the means of production and distribution into the hands of the workers themselves.
If you instead put it into the hands of dictators, it is not socialism.
Neither is it “communism”.
Communism is Socialism, plus the abolition of money as a currency, and the dissolution of the State as an entity.
Countries can call themselves whatever they want. That does not make it so.
North Korea calls itself a “republic”. As does China. As did the Soviet Union (that is what the “R” in “USSR” stands for). As did East Germany. They even called themselves “democratic”.
In fact, those countries acted more like giant corporations, with their top-down control of industry. They just planned ahead in 4-year segments, instead of quarters of a year.
Hence them being also called “state capitalist”.
Now, I will say, that Socialism on a large, nation-state level, will almost certainly fail, without external safe-guards.
It is against human nature to live for the sake of others beyond a small tribe level.
Humans are selfish, greedy, power hungry animals.
It is inevitable that sooner or later, an elite cabal will wrestle power from the people, and invest it into themselves.
That is also true of Capitalism and Democracy.
Capitalism, without external restrictions imposed upon it by the State, will invariably devolve into corporate tyranny, controlled by an uncaring oligopoly. (that is the reason why corporations have penetrated the State with their lobbyist tendrils. To defang those restrictions. To maximise corporate control and profits. Because “enough” is never enough)
Democracy, without the separation of powers and constant vigilance, would sooner or later turn into a dictatorship, once the electorate decides to vest all power into a Führer, to solve all their problems. And once people have power, they do not relinquish it voluntarily.
There is a reason why modern democracies have separation of powers. The people that designed the system knew how fragile democracy is. Recent events only reinforce that.