~snip~
In business you might lose your money but it's not something that happens often because many times we do get profits. But in gamble it's very hard to make a good career from it because it's what can make you to lose everyday if you are not lucky. Gamble is not like an investment or business that can profit a gambler but one might be lucky to have success from gamble when he gets lucky.
Plenty of people make their entire career based on the "perceived view" that they are gamblers.
So, basically they get paid by ads, or gambling casino marketing, or Youtube ads, etc...
But if you think you can actually make a living based on bets on a casino, then you are simply misinformed. The most probable outcome for a gambler is to lose all their money eventually. That's just math.