Based on how I've seen people describe China, they have a lot of "vertical slicing" going on: the parts that are good look really good and impressive, but the parts that are bad are extremely bad. They will do whatever is possible to hide the latter.

Remember that China is not a "free country" (even as much as Western nations have started to make a mockery of that word) like those of the US or Western Europe. Your experience is highly curated by default. If you're just a tourist or a businessman visiting Shenzhen or Shanghai, it's unlikely you'll have any problems - those are major international business cities!