I’m sure this has been asked before, so sorry if it was.
But from my very surface level understanding of this, communism is about workers collectively owning the means of production. If a dictator is controlling the means, do the workers really own them? To me it just seems like centralised capitalism.
Yes. This is a very important point. The failure of the Paris Commune was very influential. Quoting Marx:
So, when Lenin started his revolution, he made sure that the proletariat would not make the same mistake:
While we might look back and say “why centralise power?” At the time of the revolution, the cost of failure is very high and the proletariat understands that their enemies will use every means to try to undermine them.