Rich people who live in Hong Kong do not view their relative wealth like people who live in Manhatten, because they surely travel frequently and are thus acutely aware of just how much richer they are than everybody else on the planet, while rich people in Manhatten can get trapped in the cognitive bubble you are describing and misunderstand their relative wealth.

Singapore, being a rich island nation, works the same. If they started taxing the shit out of their rich it would certainly result in many of those people leaving the country and many, many more not setting up shop their in the first place.