Moving gold or large amounts of dollars from your basement when the country goes to hell doesn't happen. Over and over, wealthy people have had to leave their physical wealth behind when they fled for their lives.
So put it in electronic banks? Well -that "wealth" can be invalidated by an over turn in the government and new policies with the stroke of a pen. That also happens all the time in less stable countries.
It is very much in the wealthy segment's self interest to promote a stable happy society where they are currently based.
Most people don't need a lot of money to be non violent. Give them 3 squares, a roof over their head, some entertainment and a couple grand of spending money a year and they will never be a problem.
Once they lose faith in the system and lose hope, they are capable of anything. It is in every one's self interest to avoid letting people get to that state.