tl;dr The immense government-driven spending boom on building infrastructure and real estate since 2008 has made the construction, real estate, and banking sectors disproportionately large compared to the rest of the economy, larger proportionally even compared to the Japanese economy before its real estate bubble crashed. The government is going to have to enact a potentially long period of enforced austerity on these sectors in order to allow other sectors, especially capital-intensive industry like electronics manufacturing, to catch up. But the current geopolitical climate and continuing pandemic conditions might put a damper on their desire to use these new industries in an export drive. Therefore China is likely looking at a significant period of low growth like it did in the late 90s.
Low growth is the expectation for a nation moving into postindustrialism. Regardless of the potential of future socialism, right now, China's economy is still primarily a capital-driven economy. One that is, perhaps, somewhat better regulated than the bourgeois democratic equivalent might be, but still one in which the rate of profit must fall. Every industrializing nation reaches this point of slowing down. Economic growth functionally cannot be infinite. Returns, even on investment in infrastructure, must be diminishing.
And, to be clear, even resocializing the economy doesn't overcome the problem of limited returns if you are seeking to expand your economy. There are still a limited number of resources available and your ability to increase production will still be governed by the fact that each additional unit of effort invested after a certain point is still a diminishing return. The difference is that under socialism, no one is going to tell you that you'll be able to live without starving in ten years because capital's profits will grow enough - society will be organized around the production and provision of the standard of living to which we are each entitled. We do not pretend to offer a means of perpetuating growth. We simply propose that the wealth we do create belongs to the working people and that each of us has a fundamental right to dignity.