The natural progress of the world cannot be stopped. The US ailing empire has been loosing its economic advantages but now I think it has entered the nursing home. The only thing keeping the Ponzi scam alive, is the interference of the FEDs and loopholes that big corporations are going through, from bringing overseas cash to tax breaks, etc. None is helping the economy or the little guy rather is very damaging on the long run; one glance at the national debt should suffice to demonstrate where we are going. But as long as the “image” is maintained there is order in the land. But sooner or later the Yellow Jackets will be here.
China, despite being the new super power to be and despite having made strides in the last 20-30 years is not worry free. It has its own problems internally but it does not have all the international burden that the US has taken. China have not been in any wars in the last 50 years. China is not threatening nations left and right. China does not have military bases in 150+ countries. China is not imposing sanctions on any one. Say all you want to say about China, from dictatorship to communism, they have been playing it cool and super smart and it shows.
There is undeniable slow in China’s economy, in fact in the world economy. Australia is a very good indicator to what is happening east and they just cut their interest rate 25 basis points. The urbanization of the population might have peaked or close to, but the massive projects that China is working on, roads, railroads, oil lines, trains, electric energy, etc., means that China still have demand for basic material that it has been consuming for the last 20 years.
In the commodities market, China has the need to support its urbanized population. In addition they have needs to produce food that support the urbanized population. China is attempting to be self sufficient but till they do so they have major deficits that has to be filled by imports. This is where one can make some money.
Metals — 
In one shot: 
Remember that just because it is consumed it does not mean it is imported. Here is the most integrated and “perspective” figure of China’s imports. Soybeans and paper pulp are the most imported commodities that are not energy dependent.
Refs –
https://www.businessinsider.com.au/china-global-commodity-demand-rank-gdp-2018-10
https://www.visualcapitalist.com/chinas-staggering-demand-commodities/
Chinese bureau of statistics
https://atlas.media.mit.edu/en/profile/country/chn/