I thought as much...
If the where no profit in the casino business, they'll be little or no casino out there.
Well, when you lose a gambling game all the money goes to the gambling site and in case you win the gambling houses give you the winning amount. The point to note is that gambling games are not peer to peer games, hence any money lost is a direct profit for the gambling site.
So in order for anyone to run a casino, they need initial funds to pay out the winners but as the casino grows more and more people will lose money and then there won't be a problem for the gambling casino to pay to the winners as they would be collecting huge amounts from people who lose in gambling.
In essence, before the casino that was built went well, or we can say a new casino started pioneering in this industry. before, they had to prepare everything in advance. whether it's domains, hosting, scripts, games that will be adopted, you can also adopt sportsbook betting, live casino, and so on. no exception, with a license. well, what is important is sound financial logistics to finance all the operational funds that the casino runs. whether it is related to maintenance costs, other operational funds. financial logistics, can come from several investors, depending on the products we offer. or perhaps, with privately owned funds.
Well, once everything is ready, the casino will introduce itself through web advertisements, influencers, or whatever helps to make the casino famous. that is, the funds that are issued to pay for promotional services have been budgeted in advance without having to rely on losing players. well, after the process is run properly, the profits will come by itself. or it could be, as you say and I agree with your opinion.