I appreciate you taking the time to read my write-up. I want to ask, why do you claim the PRC isn't Socialist? 50% of the economy is in the public sector, a tenth in the cooperative sector, and the Private Sector is run with strict central planning and oversight from the government. Socialism doesn't refer simply to a fully publicly owned economy - it's a transitional economy towards Communism. In the PRC, the Public Sector further controls key heavy industries and infrastructure that the Private Sector relies on, so the Private Sector is subservient to the demands of the Public. The presense of Markets is not enough to claim an economy isn't Socialist. From Engels himself:

Will it be possible to abolish private property at one stroke?

Answer : No, no more than the existing productive forces can at one stroke be multiplied to the extent necessary for the creation of a communal society. Hence, the proletarian revolution, which in all probability is approaching, will be able gradually to transform existing society and abolish private property only when the necessary means of production have been created in sufficient quantity.

The reason Marxists believe Socialism comes after Capitalism is because Markets have a tendency to centralize in order to combat the Tendency for the Rate of Profit to Fall, which naturally forces the development of strategies and tools for internal planning. This naturally prepares the way for Central Planning. In the PRC, Capital in the Private Sector is trapped in a birdcage model, and the CPC increases ownership as these markets do their job and centralize. This is Marxism in action. I suggest you read the articles What is Socialism? as well as Socialism Developed China, Not Capitalism.

Also, as a side note, "Stalinism" isn't a thing. Stalin was not much of a theoretician, the proper term is Marxism-Leninism, as it is founded on the writings of Marx and Lenin primarily.

Additionally, you need to analyze who was happy to see the fall of the USSR. The answer? The West. In the vast majority of the post-Soviet populace, Capitalism brought death and destruction, 7 million people died due to it, and most long for a return to Socialism. In the Global South, the fall of the USSR was seen as an immense tragedy. The only ones benefiting were the Imperialist Capitalists that swooped in and looted the USSR's former state structures and industry for profit at dirt cheap prices.

Ultimately, I think you have a lot of research to do if you want to hold a truly internationalist perspective, and not one tainted by Western bias, which is notoriously adversarial to Communism and the Global South in general, as the West relies on export of industrial and financial Capital to the Global South to super-exploit for super-profits. This is what Marxists call Imperalism.