Yes, coastal cities like Shanghai have become spectacularly rich, but you know what, it was also spectacularly rich in 1895, in 1930, and in1947. that didn't prevent China from overall being a disaster during most of those years.
China is a very big place with a very big population, it's going to take awhile for the entire society to build up enough wealth to be considered wealthy.
China now is basically at say.. Japan 1960 , Taiwan 1980 ish overall (though with considerably higher variation .) it's going to take at least another 30-50 year for China to be reasonably wealthy, that is if nothing goes horribly wrong during this span.