They brag about all the theory they've read. Even as they expose how bad their reading comprehension is. And they think it's a flex.

It's amazing that so many people who claim to be socialists miss that despite Marx stating it pretty clearly in one of his shortest and most accessible (and widely read) works.

True, but it prescribes rule by one party (the party of the proletariat) alone. In any possible practice this rule can only be held by a party that claims to represent the proletariat, a claim that may or may not be true at any given time.

Well, not quite - we don't consider it a dictatorship because the proletariat is the largest class by population, but we would recognize it as such if the proletariat were the minority (e.g. in some kind of near-future highly-but-not-fully automated society.)