Anyway, every crypto has its own benefits but how important is it for you to have a variety of different cryptos to play in casinos?
this is my personal opinion.. Withdrawal fees are the main factor, I have tried comparing the number of withdrawal fees between Bitcoin, Doge, and Ethereum on a gambling site, the result is the highest withdrawal fee is Bitcoin (among the cryptocurrencies I mentioned). I personally prefer to trade (deposit or withdraw) on a gambling site with Bitcoin (because I'm used to it and the majority of gambling sites provide Bitcoin and don't have a problem with withdrawal fees), but for some people, withdrawal fees may be a major factor for them to decide on where they play..
When someone wanted to cashout their bitcoins into fiat from gambling rewards then bitcoin is still preferred choice because the liquidity is easier if they have bitcoin or they have to convert them in exchanges again before converting into fiat which is time consuming.