China is a massive country, with a lot of resources, the largest population, and their economy has finally woken up after centuries of anemia.
It will reclaim the top spot in most, if not all, fields.
Also, centuries of humiliation? China was the biggest economy in the world in 1900 and it still had Mongolia. China had one bad century.
I mentioned centuries of anemia, not humiliation. China had fallen way behind the West by 1900. The US had become the largest economy in the world by 1890 with a population much smaller than China's.
China's economy might have been the largest before that but it does not mean it was dynamic.
All of this does not really address my point apart from alluding to the fact that China used to be the largest economy. I'm saying that it is on its way to reclaiming its crown BUT in a position of strength compared to its position of weakness (and humiliation) in the 19th century.