Make no mistake it's not to help the other people. The ccp will likely take the rest of the money in "taxes" and then just funnel it into government official's bank accounts.
Currently China is almost completely responsible for raising people out of poverty on a global scale. This suggests that, if the CPC is funneling money into the accounts of government officials, it's mostly being used to build wealth for the people.
Besides, if the CPC has the power to limit the salaries of the wealthy, why bother jumping through hoops to raise your personal wealth when you could just raise your salary, or use a priori knowledge of the stock markets and accept "lobbying " money to raise your level of wealth like American politicians?
The Chinese national government has a surplus, but the local and provincial governments are running massive deficits and have been for a while. I wouldn't be surprised if a lot of these actions are to free up cash for the necessary wealth transfer to keep the popping of the property bubble from becoming too catastrophic to the retiring population.