Yes, Marx and later Lenin argued for complete centralization of power in the hands of the proletariat, and in Lenin’s case, an additional group of well-read proletarians dedicated to leading the revolution.

A common misconception is that a non-ML revolution wouldn’t have a vanguard, Lenin is literally just referring to whoever is the most advanced and leading the revolution. A vanguard may be a group of Anarchists trying to lead the revolution, even if they don’t use Democratic Centralism like Lenin did and advocates for in State and Revolution.

Marx also didn’t believe there would one day be a state and the next it would collapse, same with Lenin. They believed that over time the Material Conditions would lessen the need for a state until it “whithered away” over time. It wouldn’t be a relinquishing of power, but a shrinking.

Complete statelessness would have the same centralized power as Socialism, just without a state. This centralization becomes a decentralization, in that the Proletariat can democratically operate the Means of Production, which they cannot under Capitalism. If this sounds confusing, Marx makes this clear in Critique of the Gotha Programme. You refer to the state as an “other,” distinct from the workers, when it is an extension of them and made up of them in Socialism, according to Marx. There would still be a government, just no means by which one class oppresses another.

Marx was not an Anarchist, who instead believe in free association and networks of mutual aid.

I don’t believe Communism has died. It may seem that way if you see systems as static, and not as ever-changing and evolving along with humanity and technology.