I think the framing of "Pivot toward capitalist" and "pivot back [to socialism]" misses the mark entirely.

First, capitalism as a mode of production is not synonymous with market development. The presence of markets and private property is not sufficient to define a mode of production as capitalism, because they both long preceded capitalism. Under systemic limitations, they existed under classical slavery and feudalism. And they continue under socialism for some time, again under systemic limitations. This does not come from Deng Xiaoping or my rectum, it comes straight from Marx and Engels:

“Between capitalist and communist society there lies the period of the revolutionary transformation of the one into the other. Corresponding to this is also a political transition period in which the state can be nothing but the revolutionary dictatorship of the proletariat.”

• Karl Marx, Critique of the Gotha Programme

“Will it be possible for private property to be abolished at one stroke? No, no more than existing forces of production can at one stroke be multiplied to the extent necessary for the creation of a communal society. In all probability, the proletarian revolution will transform existing society gradually and will be able to abolish private property only when the means of production are available in sufficient quantity.”

• Friedrich Engels, Principles of Communism

Second, what are the systemic limitations? Put as simply as possible, the limitations are a) political, defined by the class character of the state, and b) economic-systemic, defined by what ends production is oriented towards.

Before capitalism, the state was controlled by the feudal aristocracy; a bourgeoisie existed, but was not hegemonic. It was not hegemonic politically, as it did not control the state. It was not hegemonic systemically, because production, on a societal level, was not yet devoted to the accumulation of capital and profit above all else. The bourgeoisie sought capital, but the motive force of production as a whole was directed toward supporting the maintenance of the aristocracy, above capital accumulation for its own sake.

After capitalism, the bourgeoisie exists but is subordinate to the dictatorship of the proletariat; production is directed toward serving the material needs of all of society. It should be obvious a bourgeoisie exists under socialism from the very term dictatorship of the proletariat; if there were no bourgeoisie, who exactly would the dictatorship be over, be directed against? If the bourgeoisie no longer exists, if all people are of the same class and production is sufficient for all needs, a classless society has been achieved. Communism is present.

Even capital accumulation exists: the Stalin-era USSR was certainly interested in developing industry, physical capital, and in acquiring hard currency, financial capital. They wanted continuous reinvestment in production, as capital accumulation incentivises, they wanted foreign trade. But these were not ends in themselves, they were to support the development of socialism and support the needs of the people. There were markets to some extent in all periods of the USSR’s history. The Chinese economy is the same way; there were markets throughout Mao’s tenure, and they continue to exist today. Whether these things exist is a foregone conclusion (until communism). In what proportion they exist is not the best proxy for what mode of production a society is under.

That brings us to the third point, that determining the class character of the state and the dominant goal of the economy is a clearly superior evaluation of whether a society is capitalist or socialist than splitting hairs over the proportion of a planned or public sector vs an unplanned or private sector. There just is not some clear-cut, statistical line where if you have this large of private sector, then it is capitalism, or if you have this large of a state or cooperative sector, then it is socialism. It doesn’t exist, and talking about “pivoting” to socialism or capitalism based on the proportional role of the market implies it does. Capitalist countries are not more or less capitalist than others because they have more state ownership. The goal of the economy, even in the state sector, remain principally capital accumulation. I’m sure it’s clear to you that social democracies in mid-20th century Europe were not “pivoting” toward socialism just because their state sector was growing. The dictatorship of the bourgeoisie mattered, the orientation of the economy to profit mattered. The corollary to that is that Cuba is not pivoting to capitalism because its economy is 77% public instead of the well over 90% before the fall of the USSR. Venezuela is not capitalist just because its economy is still mostly private; the dictatorship of the proletariat and the goals of its development matter. China is no different.

Fourth, it does not matter if it is a one decade-long NEP or a many decades-long Reform and Opening Up. The length of time of such a market policy, devoid of context, is not relevant to determining the mode of production. Complaining that they have not yet “pivoted” is not just misguided for that goal, it is also impatient. Communism is contingent on long historical processes; it cannot be willed into being without the necessary development. Attempting to resembles the Great Leap Forward. Yes, China is more industrialized than ever, yes it is getting wealthier, but that does not mean you can just press the button and will the bourgeoisie away.

The material circumstances determined the length of the NEP; some in the USSR thought it should continue for decades, but it did not, could not, because of the international situation. You cannot separate the Great Break and the extraordinarily rapid transition to an almost entirely centrally planned, state administered economy from the impending, foreseeable onset of World War 2. The Stalin-era economy was made for war. Importantly, capitalist countries also implemented similarly drastic changes to the composition of the economy to meet the international situation’s demands. Did the USA “pivot” to socialism in 1942 and then “pivot back” to capitalism in 1945 just because the composition of the public, planned sector vs. the private, unplanned sector changed dramatically in favor of the former? Of course not. The length of the Reform and Opening period is not relevant to whether or not China is socialist: the causes, effects, and orientation of it toward communist goals are.

So China is socialist because it is a dictatorship of the proletariat and because its economy is directed to social ends. The state tightly controls capital, is unquestionably dominant politically over the whims of individual bourgeois like Jack Ma. The state was born out of revolution and has maintained its revolutionary, one-party character. When the unplanned sector exceeds its bounds, it is checked by the state and reformed to serve social needs, like happened with the education sector at great cost to capital accumulation. Social needs come first. They are unafraid to nationalize whole corporations and sectors, unafraid to challenge capital accumulation. If China had “pivoted” to capitalism it would have joined the West wholeheartedly, it would have liberalized its politics, it would not subject itself to imperialism by claiming to be socialist, it would drop its ideology and commit instead to liberal “democracy” imperialism. The vast majority of Chinese workers approve of the state and believe it to be democratic, as in representing them and serving their needs.

The enormous increase in living standards for the whole Chinese people is unparalleled in world history. It was achieved without imperialism, without slavery, without those engines that powered capitalism’s development. It has been distributed far more equitably than the large increases in societal wealth under capitalism in the 19th and 20th century. There is no longer absolute poverty in China, there is no longer food insecurity which plagued the country for millenia. Even in the US, in the epicenter of capitalism, there is more food insecurity, to completely leave aside millions starving each year in the Global South. It has been a sustained increase in wealth for all without disruption from the anarchy of production, the boom-bust cycle inherent to capitalism. Hundreds of millions of people have experienced continual improvement in their standard of living and enjoy material abundance and security unlike any of their predecessors. If you think that is capitalist, then I would wonder why you do not support capitalism. There are more in-depth, complex explanations of its system serving social needs rather than capital accumulation but this is a surface-level examination, from my memory. These facts alone I think warrant strong support.