Communism wasn't an authoritarian movement back then, it was anti authoritarian. What is being opposed is authoritarianism.
China isn't really communist, and neither was the ussr. It's just a regressive authoritarian regime with different propaganda.
Authoritarianism is fundamentally right wing. Freedom for the right wing is fundamentally doublespeak for freedom for the oligarchs to gain power and oppress. Secondarily that freedom to acquire and impose power is granted to racists so the oligarchs have their foot soldiers.
Go look at a political compass. Authoritarianism is when you use force to push your ideals, whether they be radical/liberal (left) or orthodox/conservative)(right) ideals on a populace with extreme authority. Communism is considered left/radical, if you use government force to make people adopt it, that's using authority, hence authoritarianism. Please learn definitions and political axis before making silly arguments.
China isn't really communist because they tried it and people starved, then they had to go back to capitalism or some degree of it, but kept the authoritarianism, and effectively became some hybrid version that leans fascist.
Communism simply never works at scale, socialism can to an extent, assuming its not abused and there's a homogeneous society with shared cultural values and purpose that includes to contribute and to not abuse it. Hence Nordic socialism, which of course breaks down when you bring in those that don't share those values as its doing now. I've heard enough Swedes bitch about Eastern European migrants abusing their social welfare to say nothing of now to see the idealism fall apart when self interested parties without the same cultural values enter en masse.
Human psychology being about protecting and serving the interests of your tribe and things like "Dunbar's number" and the limit of the number of people you can literally care about and prioritize makes it impossible at scale. Families can be communist, even a small group of 10-50 people (more or less a cult or small tribe), massive populations can not. They simply are not going to work for the benefit of others without receiving something in exchange, unless you use a gun to their head, which is why all communist regimes start out authoritarian, but holding a gun to someone's head for 10-50 years won't change 200k years of evolutionary programming. Hence why Marx is good at pointing out capitalism's flaws, but he's naive and even more fundamentally flawed when it comes to prescribing a solution that does way more harm in the end.
Truth is most successful societies adopt a hybrid solution, socialism at the community or local level where everyone works for a shared purpose and contributes to the local community, whether that be through a church, small local government, etc. with capitalism that allows trade and mutually beneficial deals to happen with those outside of that community.
Communist philosophy is somewhat anti-authoritarian. It's literally about putting the everyday people in power. It's often anti-democratic though. You have to turn to Nordic socialism if you want to bring democracy in, which was developed basically as a direct result of Stalin insisting that Soviet communism was the only communism, and you could either join their (violent, awful) communism or die.
Except, Lenin, Stalin, Mao, all wrote about how important it was to be self critical, how important it was to stay grounded in reality, to make reality drive your decision making and goals.
And then they all purposely and aggressively built themselves cults of personality with the express purpose of being just garden variety dictators. They surrounded themselves with boring "Yes men" by murdering anyone who pointed out the clear contradiction between their writing/philosophy/"theory" and reality.
There's a grand canyon between what they all wrote about, and what they clearly did. The closest they ever came was Mao being like "Whoops, a lot of people died, maybe it's partially my fault" but that sure didn't dissuade him, or make him change direction.
Meanwhile their hundreds of millions of insane, murderous followers had no qualms about such a contradiction, such a destruction of reality, because they had been so poorly treated for so long in the old system that all they really cared about was tearing it down (gee, sound familiar?).
A Cult of personality is toxic to functionality. It's toxic to any progress. It's toxic to productivity and success. It's toxic to competence. It's toxic to reality.
Marx is like a doctor who diagnoses a disease then offers a cure that is worse than the disease itself. It's a bit like removing a leg to fix a broken toe. I figured this out in college thinking about it for 10 minutes, I don't get anyone whose observed human nature for 25 years not to see the obvious flaws in it and why it always breaks down.
He also fundamentally misunderstands human nature and our ability to care about anything outside a "tribe" or rather put aside our own desires for those not in our immediate tribe. It simply breaks down at scale.
Just because someone can adequately critique and point out the flaws in a system does not make them qualified to architect a working solution. Especially first draft. The problem with communism is will always devolve into authoritarianism, because its the only way to enforce people putting the needs of others over their own, not to mention those in charge will do whats best to serve their own ruling tribe.
It's how we evolved, its human psychology, and at mass population scale you can't escape it. Capitalism or trade at least to some extent incentivizes mutual benefits on a basic level, but Marx tosses out the one thing about it that works, otherwise the same problems that occur in capitalism as it devolves come about the same way they do in every other form of human governance, with groups/organizations with a shared purpose or identity (tribes) jockeying for authority and power to serve their own interests.
There's no shortage of governments where the professed ideology fails to line up with its actual policies, just look at the Democratic Peoples Republic of Korea.
China isn't really communist, and neither was the ussr. It's just a regressive authoritarian regime with different propaganda.
Authoritarianism is fundamentally right wing. Freedom for the right wing is fundamentally doublespeak for freedom for the oligarchs to gain power and oppress. Secondarily that freedom to acquire and impose power is granted to racists so the oligarchs have their foot soldiers.