Binance smart chain got low fees and is fast but some might argue that it is centralized so it might not be the best option for some people, also adding any kind of ERC-20 token won't help as they are just some tokens based on Ethereum blockchain and actually you have to pay way more fees to transfer ERC-20 tokens on Ethereum network than Eth itself, so it's cheaper to just use Ethereum.

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.