The two are - Money which they have, and then the data they hold obtained from KYC.
Data should be more secured to money to avoid scams against responsible members of the casino. If the casino care for users' data, then they will focus on ensuring nothing happens to user information. Any money stolen from the casino can be derived after a few weeks of gambling, at the same time casinos has also get away with stolen money sent into the casino so if they lose it as well won't be a big deal.
If members fall for scams as a result of casinos not securing their users data, then they will lose their reputation.
It's clear that there's no casino platform that releases the data of anyone who gamble or verify with them to the public, the thing is that many people who is into gambling get scared of casino being releasing their documents to people, you have said it all there's no casino who will release their database to anyone, even though its a fraud case I don't think that they will realise your information, except that the casino platform is the one looking for you
If casino releases the data or documentation of someone who patronise them, that's means such casino platform is not ready to gather traffic, many players will be afraid of them, and as result of such they will lose all their customers, because they have no reputation again.