You are right, mate. I think a gambler should even withdraw their money and keep it in their personal account even when they don't have bills to pay yet. The reason is to prevent themselves from being tempted to gamble when they have that money in their casino's balance. For example, if one has about $300 in their casino account, they could be convinced that it is a huge amount, and before they can spend the money, they must have multiplied it by 2x, and by the time they decide to start gambling, they can lose the money or still multiply it by luck.
So personally, I don't even see any reason why anyone should leave money on their casino account when it's clear to them that they are gambling with it at that very moment, it's a risk tjay goes beyond every reason one can think of, for instance, even without gambling ans losing all the money, they casino itself could be hacked, or if the casino management is a crooked one, they could empty the account (depending on how long the money is left there), and when the gambler returns, they will claim the gambler never had any balance, that it could have been a system error that showed a balance on the gamblers account.
So in essence, my take is that we should never leave money on casinos, money we are sure we are not gambling with immediately, better withdraw to your private wallet and keep it there until you are ready to use it.