The driving distinction between capitalism and socialism are the following:

1. Which class controls the state?

2. Which form of social ownership forms the principal, ie rising and dominant, aspect of the economy?

The socialist market economy of China has, as I already demonstrated above, a working-class state with public ownership as the principal aspect. It thus falls squarely into how Marxists understand socialism. This is reflected by how the working classes are the ones seeing the primary focus on development and upliftment in China:

State capitalism, on the other hand, may have strong public ownership, but ultimately will be a capitalist dominated state. This is reflected in how state-owned industry ultimately is run in a manner that supports the capitalist class. Famous historical examples include Nazi Germany, as well as modern Singapore and the Republic of Korea (for at least the first few decades).

This is why Marxist analysis is enormously clarifying. Without understanding Marxism-Leninism and Mao Zedong Thought, it can be difficult to understand China's social structure, as well as why the majority of communists support China. If your understanding of socialism looks like a fully collectivized, horizontalist system, then anything that exists in real life gets measured against such a model. However, socialism is enormously dynamic, as it is a transition between capitalism and communism, and thus there is no "one" socialism, not even within a single socialist state!

All countries have censorship, none have freedom of speech. The class that controls speech is the class that controls the state. In capitalist countries, capitalists use dominance of the state and private media to disseminate ruling-class ideology. The same happens in socialist countries, only this time it's the working classes with domination over speech. "Freedom of speech" is generally a euphamism for allowing capital and money to dominate the speech of society. This is also why the Chinese population feels very positive about their own system of democracy:

The reason China has billionaires is because China does have private property, and a rapidly growing economy. What's important about China is that it is consistently the lower portion of society that's actually seeing the greatest gains:

This simply does not happen in capitalist countries, especially not in the last few years where private capital has been astronomically expanding. China's people-centric development has resulted in the strongest and most rapid rise in living conditions for working people in the modern world.

Jack Ma is an example of worker-rule in China. Jack Ma began undermining the socialist system and publicly advocating for reforms that would strengthen the autonomy of private capital. The CPC ruthlessly punished him for trying to undermine worker power, and stripped him of his speech. The same happens in reverse in capitalist countries, the state regularly strips working people of their right to protest and speak against capitalism. There is therefore no true free speech, and therefore it's important that the working classes control speech.