Yes that's correct. That's because when people start getting to know cryptocurrencies, what they know is bitcoin and then they get to know altcoins and what coins are included in altcoins. But with the high cost of gas from ethereum, I think maybe ethereum users to gamble can decrease because they feel the high cost of gas. Meanwhile, if they use bitcoin, the transaction fees are not too high. But whatever it is, these two coins are the most popular which are often used for gambling next to the other coins.