And what would be that problem? That sounds like wishful thinking. The median age of China is below of that both the US and the EU.

https://en.wikipedia.org/wiki/List_of_countries_by_median_ag...

A significant fraction of the US seems to have problem to adjust to the notion that in the next decades China will become the clear number 1 country in many fields, and the US will be to China, what Germany is to the US.(Similar on a per capita basis, about 1/4 in absolute numbers)

Wishful thinking is a terrible basis to plan.