Any casino is created primarily to earn money for yourself. While some players earn money, others lose their money and in order for some players to earn a lot, others have to lose a lot.
It's partially correct, because you're like telling us if the casino can control the outcome which make the winner can earn more than the losers, it's not 100% will be like that because there's still a professional gambler can beat it. This is also the reason not all casino is survive, some closed due to the gambler win a lot, some closed due to internal scam, some closed due to hack, and some closed due to lack of gamblers.
In the above listing, you seem to have highlighted 3 categories of persons in a casino. The house (casino), those who win and those who lose. Somehow, loosers are highlighted to be the ones that eventually funds the winners. Like, there loses provides the fund to pays the winners.
But, casinos do shit themselves and run out of funds too, courtesy of those abusers that sort out for loopholes in casino programmings and faucets. Somehow these guys often wins to a point that, some casinos could go out of business and lose there ability to pay. Also, a point to this is out of the fact that, they aren't getting much patronage.