I think that if a person adheres to the rules of his religion, then he will not play gambling. The rest can gamble either for fun or for making money. Because it is very difficult to combine earnings and entertainment.
It totally depends on the religion and their belief. There are other ways to entertain ourselves if we are just treating gambling for fun but because there's money to risk it became exciting. In my view, money that earned from gambling is not different in other source to earn, its just that how you accumulate it is more on luck since you have no assurance if you'll going to grow your money or not.
At this era, we can gamble even we are at home, using online crypto gambling websites. There are many gambling sites out there that you can visit if you want without knowing your family even it is against your religious belief. I did not consider that the money we had earned on gambling is dirty money. Yet, it is still considered as a source of income, because that is not a crime.