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.