If you take a poll for this the Bitcoin casinos can easily beat your Ethereum casinos, I have not played on Ethereum based casino yet, the Ethereum fees are just outrageous I'm a small player and fees just eat up my allocation, and besides people are more comfortable playing in Bitcoin casinos they are popular and the majority of casinos already have these two coins, so there's really no competition for both coins.
That's because many of us are fond of using bitcoin for gambling. Apart from bitcoin, many also use ethereum for gambling but currently, the gas costs for sending ethereum are very high, which may cause the use of ethereum for gambling to decrease. In addition, we can use other coins that can help us minimize shipping costs and I think the use of these altcoins is not as popular as bitcoin or ethereum. But it is indeed very difficult to compare casino bitcoin and casino ethereum because each has its own advantages and disadvantages and only gamblers know what they choose.
Not just that , aside from Bitcoin and Ethereum there are lots of coins to use that has super low fee so why need to use these 2 when we can obviously choose other altcoins that can save us a lot in gas fees?
and also after Ethereum fee blow up last year ? i think that we need to have at least other choices when we engage in crypto gambling , this also helps us have better understanding of altcoins.