Hypothetically speaking, if the average Chinese person was as wealthy as the average American, how would that affect the world economy and geopolitics? What is America so afraid of?
China clearly support Russia in their war on Ukraine despite pretending neutrality. Europe should be afraid.
China is doing lots of other geopolitical things that you should be afraid draws you in.
Meanwhile USA...
But actually it will be embarrassing when China puts an end to the "freedom of navigation" of all those US Navy ships circling their borders.
Everything. The whole empire exists on the basis of exploitation, and existence of enemies. The US military industrial complex has immense power, and it needs a reason to exist, and keep existing.