“Transitory dictatorship” is left pretty vague by Marx. But what he is talking about class dictatorship, not dictatorship in the literal sense of one person in a country having unlimited political authority. There are so so many anarchists and liberals that do not understand this because they continue to conflate the word “dictator” in the way Marx meant with how Western capitalist states weaponize the word.

Dictatorship of the Proletariat is seen as a law within Marxism the same way there are laws within other scientific fields. It’s the acknowledgement and observation that after political power is seized by the working class, class relations do not automatically just disappear. The working class will need to sustain and protect the revolution until those class relations from the previous mode of production wither away over generations. History has shown us this since the beginning.

A centralized vanguard party is Lenin’s well-tested contribution to Marxist theory on how to achieve and protect a socialist revolution under seige by imperialism. But that doesn’t exclude the possibilities of other tactics in the future.