As was seen recently in Sri Lanka when the corrupt ex-president tried to run away by plane, you can't if the people hate you because the plane doesn't fly itself from nowhere - it needs mechanics, air traffic control, passport control, pilots, etc. He managed to escape with a military plane, but that's unlikely to be an option for your random rich person not ex-military chief.

And Europe, especially France, has a rich history of getting rid of upper classes on occasion.