Check the casino's tabs and pages and see if they're showing how much they've got in their bankroll. Some casinos and dice sites do this and if you're not satisfied with the current one that doesn't show it to you then leave them. They don't have the obligation to show how much they've got especially the reputable ones because we know how huge they are. I think it's not a matter to me as long as I know where I am gambling and I have an idea about the track record of the casino. Btw, this topic should be on Gambling Discussion.
I doubt they'd have that much leeway for their customers, although I guess some of them may have features like that, but they really have no obligation of every showing us how much money they got in the reserve because it's not something that gamblers are actively looking for, especially for reputable gambling sites like you mentioned.
Casinos that are oldest may be facing, not a lot, but some sort of losses due to crypto crash and I'm saying this as casinos just don't keep the deposits as it is as they also need to pay for the withdrawals that take place on their platform. So it really doesn't make sense on suspecting casinos about whether they are on a loss or still making profits. What happened at FTX was a different story, but it'd be really stupid to ask a casino to show what do they hold, because except USDT and other stablecoins, any crypto that a casino holds does not have a fixed price and something that's variable in value will definitely make them look in deeper losses even though they are in profits. No casino would put out their balance sheet in front of you just because you are demanding it, you'll either need some serious accusation or strong evidence against the casino whether they're involved in any foul play or money laundering activities.
I don't think they'd have that much trouble over the market crashing. I mean apart from their cryptocurrency holdings they shouldn't lose money in the process because rain or shine gamblers will come in and bet on their site. And even if it were the case I don't see the point of ever digging into whether a gambling site you frequent is still making money, breaking even, or on the verge of bankruptcy.