China is at an awkward point, the one child policy was a success at the time and let the country lift itself out of poverty, but not high enough. So now they're going to deal with rich country problem (lots of old people and high dependent/worker ratio) but with the income of a middle country. I'd resist going "its all communism fault" and instead would say "its in large part authoritarian fault".
China has a bad habit of shooting itself in the foot for no particular reason, the most spectacular recent one being when they decided that tech company were too successful and decided to kneecap a bunch of them, which accomplished nothing but definitely sent bad messages, both to investors (the government might destroy all your value at a moment notice) and to the populations (don't you dare become too successful). Now all countries have these kind of issue, but democratic countries tend to have a lot of inertia and momentum built in them, so that crazy stupid idea they're leader get take a lot of time to be put in practice and often become blunter. But authoritarian one have none of this, and so when the great leader gets a dumb idea, it gets carried out. And this is far from the only example, for profit education has been essentially made illegal and video game have been severely curtailed.
Then there's the quasi ponzi scheme nature of the construction bubble that can only work with ever growing population. The government could help this along by making it easier for people to move from rural area to urban center, fill those empty tower, but here again they're shooting themselves in the foot by making it very hard for people to move between provinces and city.
It a bit hard to predict what will happen next, usually when country hit rough patch people will start to agitate for change. But China government is so strong, especially with Xi being so well established, and censorship so thorough, that there seem to be no agitation. Even with joblessness of youth reaching such high number that the government decided to stop publishing the number, there doesn't seem to be any chance of something like 1989 happening again, and even that was very small and unlikely to bring any large change. The population seems more apathetic about it all, young people saw their parent work hard so that they could have better live, but they didn't really get better life, so they don't see any reason to work hard themselves or start a family.
The danger is that the CCP decide they need something to distract the population and they start looking at reunification of Taiwan as an easy target, but its not clear they even need to. With Xi and the CCP being as secure they have ever been, there's really no reason to. For the time being they seem to mostly focus on economic independence while at the same time trying to push to preserve they status as a large exporter and they've been having some reasonable success, notably in electric car and solar panel. More western aligned nation are trying to decouple, but they have to chose between very expensive workforce in western aligned country (which usually just mean they'll use robot) or going to other cheap labor country, which tend not to have poorer workforce and supply chain than China. Either case, price are going to rise which might fuel higher inflation for the rest of the world for the foreseeable future.