China is not going to collapse. That is just deep state propaganda.
Just look at the fundamentals. They have enough people, they have enough ability to produce and grow food to feed those people. They have at least a group of people that have achieved a high-level of education, skill and technical ability, its a not China of the late 60s that can't make ball point pens. The have powerful government that will be able to by fiat redistribute wealth in a way that prevents actual mobs of staving peasants, and culture that will all them to take heavy handed actions against agitators without it really damaging the states support politically.
This is not to say that they don't face serious demographic headwinds; because of many past bad policy choices. I think the Chinese economy is likely to slow down a lot - unless they make more imperialist moves. Which if successful could turn them into the ascendant super power, or could be their undoing. If they do nothing but stay the course they are on currently however they will come thru just fine perhaps after a couple decades of restricted grow while the demography works out. The ONLY things they need to get right or are 1) turn their technical investments toward deploying more mechanized agriculture, and 2) keep encouraging people to have babies, so the population reverts toward a younger mean.
I would be much much more worried about our own house. We continue to spend and operate as if the rest of the world lies in ruin after WWII and we are not just the military super power but the lone industrial power. This has not been the case for 30+ years maybe longer depending on when you want to say 'the American century' begins and ends. Look at economy. Look what a little supply chain disruption does to the purchasing power of our dollar. Look how rapidly the world is moving off the dollar. Realize those supply chain disruptions were largely in elastic items, not food stuffs; we grow our own mostly; but we are told constantly the US ag industry depends on migrant workers and illegal aliens. Now imaging the inflationary pressure if we stopped massively importing slave-wage labor and had to pay people minimum wage to pick berries... Look at how much of our economy is dependent on trade conditions that only exist because of our massive military investment in preserving the world order that isn't matched by the EU. All you have to do is look at Libya and Ukraine to see the EU can't and won't provide the security required to keep our trade focused highly specialized economies functioning. We have to do the heavy lifting and we only accomplish it with massive deficit spending with not hope of balance in sight. Its the West that needs to worry about the wheel coming off not China.