Actually, the gov is taking actions and it's quite strict. One example is, my friend's bank account was AUTOMATICALLY withdrawn a couple hundred RMB from last month, to pay the tax AUTOMATICALLY.
Lived in the US for a couple of years, I can't imagine IRS doing that to my bank account
Also, to the @awsedr58479 's question: Chinese consumption tax is crazily high. Most people don't know they are paying it since it's structured into the price tag. Also the companies are paying quite a lot of taxes