Afghanistan doesn't have strategic value anymore. During the war against terrorism, the US rallied allies and got permission from Russia and China to topple the Taliban. Both central Asian nations and Pakistan were forced to cooperate and provide logistic support for the US military. However, Afghanistan is a landlocked country without a port or direct airspace corridor. Therefore, Afghanistan can't be a springboard for invasion. That's why the failure to topple Iranian government during the Arab Spring and losing the support from central Asian nations and Pakistan have doomed strategic value of Afghanistan.
I don’t think even Trump was delusional enough to think anyone could actually invade the Chinese mainland. That was never the intended role for Afghanistan.
I think all the recent MSM articles out of the blue of Chinese military intervention in Afghanistan betrays their original game plan there. Afghanistan’s puppet government was always supposed to fall, it was just supposed to have lasted a whole lot longer, and been a gradual process lasting years (probably 6, since the Soviet’s puppet regime lasted 3, and democracy automatically is at least twice as good, which would also have that happen right around the time Trump’s second term is supposed to end, so they could blame it on him, and massively boost the democrat’s chances of making a comeback).
Afghanistan was supposed to be Syria 2.0, where it’s gradual, inextricable collapse into anarchy, with CIA transplanted and natured anti-Chinese and anti-Pakistani terror groups making sure that chaos spills over the ‘right’ boarders baiting China in militarily since China was supposed to fear instability above all else per western consensus.
America’s pullout was to lock in that collapse and help them resist inevitable allied pressure to stabilise the situation; and create a firewall where the situation was supposed to be nice and stable for a number of years, so they can avoid Vietnam parallels and also wash their hand of blame for its future collapse; while at the same time making military intervention more appealing to China since there won’t be American forces to get in the way, and also to avoid a Russian scenario where they are the undisputed inferior power where China would enjoy escalation dominance so it would be the Americans who would have to worry about being on the receiving end of foreign air strikes and having to meekly back down even if they do get hit since they cannot win the ensuing fight if they push back.