I only use Bitcoin and the occasional dogecoin as a coin if I want make a deposit so I don't feel the need to see the casino where I play adding another coin
Casinos want variety for payment system so that their games will be easily patronised and so they add dogecoin because of the fees that is very good for gamblers. Not every gambler have bitcoin because some trade dogecoin and transfer same to gambling account to play. So it is still in use as option for some gamblers.
Exactly, they can add Shiba Inu as well. These meme coins are having may holders right now ever since Elon hyped it, the hyped doesn't stay for so long but it still has a lot of traders and I think it is going well in the market especially for DOGE. Doge is not yet known a long time ago, but now I love to use that because of the fees and the transaction time that is more faster than the other.