If you hold your balance in crypto, it is like gambling twice: the games you play/bets you place, and the volatility itself. In a bull run it is great for the customer, but it can also mean losing your profits if the bears take control of the markets. On the other hand, holding stablecoins or fiat is more safe, but less exciting.
To me, the best would be the ability to swap the deposited coins inside the casino as you please, so you could choose on the go the risk you want to accept. But casinos are not exchanges, and I don't think this is a usual feature.
Stablecoins seem the safest option to avoid impermanent loss due to price fluctuations and it's what I prefer.