Economic growth is just easy to check data. Many people are completely unaware even of that. Not saying you specifically are. If one's interested beyond that, could look into other indicators such as education, life expectancy, etc.

China's relaxed some sectors and not others depending on their importance and the competency within.

Generally markets and competition do well in figuring out how to do something we don't know how to do well and cheap. Once we figure that out for some product or category, profits fall competitors fail and consolidation sets in, cost of production falls further due to decreasing duplication and increased scale. At that stage, you have to re-establish control or the monopoly begins draining resources from the economy by raising prices. I think this is what China's doing. They do a high level plan on what they want to develop, get their centrally controlled bits needed in place, e.g. capital from banks, raw resources for batteries, then let existing or new companies enter a competitive market to develop the thing. We saw this occur with EVs. I don't think they've reached the consolidation point yet.

A sector that hasn't been relaxed for example is banking and for a good reason.

But beyond relaxing control, the other very important thing that was relaxed was foreign direct investment. Getting factories built in sectors you don't have by foreign firms, almost always as joint ventures with the clearly stated goal of knowledge transfer. Personally I think this is likely a bigger contributor to their economic explosion than planning changes although it also requires planning changes itself.

On Walmart, I think what you're looking at is the feedback mechanism of shop/factory data going up the stack. A Walmart store has no capability of doing the planning needed to get a requested amount of a certain good on its shelves, beyond requesting it from Walmart HQ. Walmart HQ computes and directs everything from telling how many thousand plastic trays a factory in China should make, to eventually getting the 50 requested by a store in Bumfuck Nowhere delivered. Data feedback mechanisms exist in every operation of meaningful complexity. They existed in the USSR, they exist in China, they exist in every corporation I've worked in, currently automotive. Every large corporation takes data from its operations, either through people or directly from processes, or both, or from their products themselves, computes projections, decides what to make more of, less of, what program to cancel or start, what input resources to get more or less of, how many people to hire or fire, all in order to support the desired new projection. Then they turn that into their expected growth numbers for the next quarter and spit it out during their investors call.