You're missing the most obvious reason that's far more important: Anyone smart and Chinese knows that there's a very decent chance that the system collapses and/or the government steals all your money and possibly your life. In the US and Canada, it's extremely uncommon for the government to steal a rich person's money and even life, and it virtually never happens without a public trial.

Anyone smart, Chinese, and with resources is looking for a way to not be subject to Chinese legal/government jurisdiction, and if you were in China, you'd be doing the same.