Just to let you know, casinos don't give away wins bigger than their bankroll but they have the wins like jackpots and stuff set based on their bankroll, they can even set the maximum bet amount if they know that they don't have a very high bankroll and won't be able to pay the player if they manage to get a win. That's why, even if a user wins a jackpot on the very first bet of a casino, the casino won't run out of money just because of that single win.
However, I do agree that a casino must have a pretty large bankroll because it is important for their reputation if they are giving out very small amounts for big wins and aren't allowing high bets, they will most probably lose a lot of gamblers just because of these restrictions which might be new to some.
The fact that their still rely on the bankroll to provide liquidity to settle ther bets still make it ball down to the samething, although, casino have systems and mechanism is place that will keep them in business even though their may have low liquidityy to pay for jackpot winnings, but also the availability of the jackpot settlements will sometime depend on the availability of such bankroll.
That is why in some cases, jackpot winners are made to wait for a long time to be able to withdraw/cash out 100% of their winnings.
Yeah, I was going to say this same thing you pointed out in the sentence of your last comment, though I still very much agree with all that you've said, at least for a fact, someone in my area where I live some time won a little above 30 million naira on one of our local local online sports betting here in Nigeria, when he tried withdrawing the money, he was asked to wait 14 days before he can place a withdrawal request, after the 14 days, he places a withdrawal request, the sporting betting company was paying him 500,000 naira every week until the entire 30+ million naira was completely paid ..
The company didn't say why they did this though, but me and every other person Thay heard the story believed they took this approach because the company lacked enough money to pay off the winning at ones , and I think it is still very better this way, than for the company to begin to look for some sort of allegations to lay on the winner, as a way to excuse themselves from paying his or her winnings.