My true definition of democracy is direct democracy. Once you start giving power to a representative then you stop being democratic. And that includes power to survive, eat, have shelter, have vacation, have time to study and pursue creative things.
But unless we can instantly communicate like the Protoss can then no, we can't achieve 'rule by the people'. However, it's not simply a choice of Direct Democracy, 3-branch system, 1-party system. We can have system where there is way less concentrated power (again, emphasis on power including many things like education in critical thinking).
Having said that. Yes China is not a democracy. Nor any other country. It is a question of how power (again, my emphasis) is concentrated and the potential of corruption.