1) you can't trust most of China's numbers. They are in full only-show-numbers-that-please-dear-leader mode. The tarriff war that is brewing between the US and China is about China doing some last-gasp production dumping before economic collapse, although that argument could admittedly be dressing up numbers that don't support their arguments of the pro-collapse geopoliticists.
2) China's rattling on Taiwan is very similar to the demographic motivations of Russia's invasion of Ukraine: both are suffering huge demographic collapses soon, so this is the last generation that the country can use for an offensive war. Yes, it is utterly stupid to take a demographic problem of a shrinking younger generations and KILL THOSE PEOPLE IN A WAR to exacerbate the problem, but strongmen just concern themselves with keeping their positions, not how the nation as a whole thrives.
3) Sub Saharan Africa? Like, that is 5,000 to 6,000 miles away? And an area that will become increasingly utterly uninhabitable due to global warming. The Belt and Road is a complete failure, again, because the infrastructure was poor and the payoff isn't there. The countries are just going to walk away from China, and instead of paying them back or restructuring (China won't restructure), they'll join a Western bloc against the Chinese.
Belt and road, for the reasons described about the complete inability to defend multi-thousand-mile infrastructure lines like pipelines and rail, is an impossibility to work in Asia. Even if the political and security challenges are solved (which requires a nice intercooperation and low-war world, which we are NOT headed for right now), it isn't even remotely economically viable.
4) Ultimately war games are meant to be lost. Because that drives the exigent threats to American hegemony that drive the near-trillion-dollar defense and intelligence budgets politically. Yes you don't want to underestimate the enemy, but look at what is going on with the Russian army under decades of totalitarian corruption and incompetence. China is headed down that path, but doesn't want to stop at a neo-western society like Russia has, they want full on North Korean dear leader control.
5) The fact of the matter is that China imports its oil through the Malaysian Staits/Straits of Malacca. Go look at the map. No matter how much shipbuilding China has, no matter how many cruise missiles, they won't get oil through there if the West decides to impose sanctions.
6) Finally, there's India. India of course hates China as well, and India is modernizing its military under Modi and it alone would jump at the chance to choke China in the Indian Ocean.
China is not collapsing overnight. It is not economic armageddon, these things are always slow slides. I mean, in theory it could because mass starvation at the hands of the communist party is in China's 20th century history, and it is actively occurring in North Korea.
The point is that the old world political economic order, and by order I mean stability and structure, not the illuminati evil control council "order", is over. Russia invading Ukraine, COVID disrupting supply chains, and China becoming aggressive and authoritarian ended that. That era, a solid 75 years between bipolar Cold War stability and unipolar post-Cold War is OVER.
Every five years that go by in China will decrease their military effectiveness by a substantial degree, because of authoritarian degradation in chain of command and corruption, because of demographic reductions and disruption.