You can either make a bitcoin casino or a crypto casino which has most of the established coins.
But there's no point in making an ethereum casino at all. ETH fees are huge when the network is congested.
People would rather stop gambling on your casino at times like these which would directly result in a loss of revenue for you.
So the best thing to do would be to create a crypto casino but even then there are so many casinos already.
So the competition is really tough. Might as well think of something unique but a n ethereum casino is a bad choice.
I think creating or building an ETH casino is not OP's goal or purpose but rather looking for opinions if playing in Ethereum casinos is somehow convenient too like playing in the usual bitcoin casino. We really are concerned about gas fees in ETH and I think there will be no solution for it for now. Depositing ETH to an external service will likely cost a huge fee compared to usual.
The only advantage of using ETH casinos, as I mentioned already, is the ability to link our own wallet like Metamask into the platform making the deposit cheaper and much safer. But I doubt gamblers really prefer that way that's why it's now up to OP if he will test the experience of gambling in an ETH Casino.
Well in that case I think it's best not to try ETH casinos at first place.
Firstly there's a risk that not all casinos might be genuine, some may even run away with our coins.
Secondly, if we don't have a control on ourself from gambling then we might end up gambling all that we have in our wallet.
So these are some strong reasons why I wouldn't use a ETH casino.
It's better to deposit a small amount to gamble and then make the other deposit only when it is all gone.