Nowadays it shouldn't just about the coin, but about the provider as well. if a website can have few options like binance chain, ERC-20 i think it should be better
Casino websites should accept some coins with privacy features and some other coins that are just fast for sending/receiving payments so that every customers is able to use a payment method that suits them the best, whether they choose based on their fees, privacy or speed should be up to them.
What coin like monero? Maybe thats a good option though I don't see much user use this as an option but for now many casino are slowly adopting a good coins like xrp,trx and ada, also doge got a good tracks right now so maybe those casino consider this since this one will give convenience to their bettors and might they will make them stay since people don't like to be hustle.