We have democracy in the US to elect basically stand-ins to represent the capitalist class, because our democracy and all the interconnected institutions we have are built for the capitalist ruling class specifically to wield power. We don’t have a way of electing someone who can, on a broad level, give us more power over our economic and social lives (except in rare instances at the local level for sporadic, hyper specific causes. But never anything foundational). We can’t change the overall economic and political paradigm we experience through our democratic process. It is literally just a lie of propaganda that we “might have this power if we just vote hard enough,” a lie that allows the ruling class to keep the working class docile. These communist countries however, in their different ways relative to their own historical development and social structures, have, through the power of revolutionary collective action, built institutions that allow normal people of the working class to express their will over their own economic/social circumstances rather than a capitalist class. And socialism is that. Whether that’s the worker council Soviets of the USSR, the community collectives forming and ratifying changes in Cuba, the bottom-up stages of democratic voting process in China, etc, they are expressions of the working class wielding power in a way that the capitalist class does not. That doesn’t mean it’s as simple as voting in good or bad economic/social circumstances of course. Most of the power of the world is aligned specifically against them, violently, and there is no hardship too inhumane to inflict on the people of these countries by the West/Global North. The US is more democratic if you use the idea of that which the capitalist class has defined for us. These other countries are more democratic than the US if you use the idea of that which the working class has defined for itself

Edit — just to drive this home further, the capitalist class in the US/West/Global North goes to great lengths to perpetuate the implied (but untrue) feature of our system that the working class could have whatever power it wants, if only it were able to organize itself and vote that reality into being. That is the root of the difference here — that simply is not possible in our system and the capitalist class knows that. But the US presenting our system anyway as something that hypothetically could allow for that, allows them to say hey our system is more democratic than the system of one of these other countries because they don’t allow for the hypothetical reality of the inverse of that — for the capitalist class to vote itself into power in the same way. That’s of course an obvious farce. How those countries are set up is already an expression of the will of the people over the capitalist class.

I’m of course really generalizing here when I say “how they’re set up.” Every system has its contradictions that place it more or less on a spectrum of how the working class is able to express its power within the confines of its own historical development