Firstly, China themselves say they have not achieved socialism. https://www.equaltimes.org/china-seeks-to-become-a-socialist?lang=en
I personally am extremely critical of China’s economic system, they are effectively the most Neoliberal state on Earth. A tenet of neoliberalism is that Capitalist investment raises the quality of life in developing counties, Deng agreed and opened China up to investment.
The Chinese labor force is stuck in wage slavery and awful conditions just the same as much of the global south in the name of economic development, they offer cheap labor and in return the CPC gains economic power.
China currently is much like a social democracy, they uphold capitalism and believe it is the best option for rapid development and pass some social programs to keep the proletariat placated. ex. Their healthcare system is pretty much identical to the heavily criticized US system.
Therefore imo, China Ideologically is a leftist state, but their doctrine calls for, much like the USSR, a transitory capitalist state to achieve socialism. China state media states they are in this process
To say China is "the most Neoliberal state on Earth" is a disservice to the massive outpouring of government investment into infrastructure projects, something neoliberal states practicing standard austerity economics with heavy reliance on privatization are less inclined to do. You can argue against their less than ideal labor conditions, but that's not a feature of neoliberalism.
China admitting they are not fully socialist is a fair and honest assessment on their part. You do not flip the "begin socialism" switch, just as you do not flip the "abolish the state" and the "abolish commodity form" switch. Socialism is a transitional state from a previous transitional state. It must be built upon as a process, which requires a form of controlled capitalism, supervised by the state, to build sufficient productive forces so as to gain independence from international trade. You cannot seize the means of production if there are no means to seize in the first place.
I can't deny China has sold their working class to the lowest bidder in the past. There's not much I can say in that regard, but I'd say they felt the need to rip the bandaid in one go, sacrifice a generation or three as disposable labor for future generations to reap the benefits, which are only just now manifesting.
Correct. This is a standard interpretation of Marxism-Leninism, and orthodox Marxism. Socialism is an onging process in multiple stages that must be built upon before "true socialism" (let alone communism) can be achieved.