If I may ask, why do you like to invest and earn interest on crypto casino sites?
It can be a relatively lucrative and low-risk (depends how you're treating it) way of making some money from the coins you already hold. The more established casinos that accept investments are also less likely to run off with your money, so the risk with plain theft is relatively low, though there's always a chance that your investment could be wiped out if a whale wins a large amount of crypto on whatever site you've invested on.
You could also just put your coins into something like BlockFi for interest on your coins as well; I believe the site's offering up to 8.6% annual compounded APR at the moment for investments under 5 BTC or something like that, and it's potentially lower risk than investing in a bankroll.
You stated well all the possibilities, that's why I stop investing in a casino now.
We maybe believe that casinos always wins and as the have the house edge, but we need to make sure we have a decent investment and adjust the risk exposure to ensure it will not easily be wipe out, in the early days, I have invested in safedice and there's a feature to adjust exposure but that would only result to a lower profit and I was not contented on that since I don't have a big amount of money to invest to satisfy myself from its profit.