Some of them casinos provide an option for the investors to participate in the casino's bankroll. But of course the casino/owner still takes the biggest share and gives the shareholders less then what they deserve theoretically. That's because the owner spent time and money to make the casino going and it has various expenses. Let's say the casino has a $100k bankroll. If an investor invested $10k into the bankroll, he should get 10% of the profits. But he gets less than 10%. Some casinos used to do this but I don't there are many left.
If you are a gambling platform running for a long time I guess its not ideal because you just exchange a small amount in short term than in long term, yeah what if they will run the funds still its a short term imagine those earnings they can get into daily active users or players into their community. Also its unexpected both it depends on the owner if they will give it back to their users but of course for the KYC users only might probably.