And this mindset is one of the things that has consistently fucked serious socialist governments once they do gain power, is the thing. (Another of the things is the CIA but that's another conversation.)
Because if you are unwilling to try to build institutions that can fluctuate and evolve and potentially be used in ways that aren't true to your vision, you not only have to institute tyranny, you have to build your entire system around maintaining your tyranny forever.
And once all your other goals hinge upon retaining power forever, they become subordinate to it.
At which point there is no realistic future to the Tyranny Of The Proletariat other than the tyranny of you personally. Which means you are going to 1) liquidate your own peasants or whatever similar scenario arises in your context and later 2) be overthrown and leave no useful institutional legacy, because you founded it all on virtue-by-fiat.
The self-cannibalism of ideological purity is never pretty, but in the context of government it's particularly bad.