for example in Macau, this is one example of how a country benefits from the presence of a gambling industry in their country.
Macau is a very developed nation under China, but using Macau as an example is what I do not understand. All countries that legalize gambling and collecting tax from gambling are benefiting from gambling despite that people in their country will be employed by the gambling sites.
We all know how gambling works, and it is pure luck, you can't get profits every time. So for me, I really discourage people who fully rely on gambling as only source of income.
They will learn their lesson and know how gambling is when they lose all their money used for gambling. Gambling is not a job. It can not be used as a source of income.