There's also the attached costs that come with the position of global hegemon. The US has been basically eating itself for the past 50 years to maintain power projection through military might. I think this is something China is acutely aware of. Even though they are spending a lot of treasure and manpower on building up their military force, they are doing it only as a deterrent to an ever-increasingly belligerent US (and this is obvious if one looks at what capabilities they are putting on their new hardware, that are primarily designed at defending and operating in Chinese space). They've stated many times that they'd rather be building commercial ships than aircraft carriers.