Singaporeans work hard and also because it's one of the financial hubs of the world that there are opportunities to make money, I did work for a guy here that his father started his own version of ASOS clothes in Singapore and it took off and he became a billionaire though you are right about generational wealth as the son ended up with the money when his old man died.
These guys who splash so much cash on escorts are probably because they are lonely and so busy tied up in the business or work that they can't manage a proper relationship so they have ones for an hour at their convenience.
Some people I know work hard, two mates of mine run their own plumbing business, just the two of them but they work hard for their money and roll around in rolex's and have their money tied up in good investments.
Don't ever become envious of another person's wealth because you should focus on what you have in the moment.