See also, Japan in the 80s, West Germany in the 1960s, _Italy_ in the 60s (that one was particularly short-lived), the US in the 40s-50s and to some extent again in the late 90s, etc etc. "[Country] will outcompete the whole world to the extent that the rest of the world will literally collapse" is a long-running idea, but doesn't _really_ make that much sense.
Though, also, I kind of thought that people thinking this about China had peaked in the '10s at some point (as with the other examples, China's GDP growth rate has now moderated). Move onto the next country that's going to take over the world, already!