Those days are not actually gone, there are several casinos where you can gamble with Dogecoin and even Shiba Inu.
Stake is one of them, you can deposit Doge and Shiba and take advantage of low fees of the Dogecoin blockchain, so there you have an option from an online casino which is quite popular around here.
Like I said earlier, not an advantage when there are alternatives like Litecoin, Tron and many others which have high utility, but for casinos to have more deposit option for cryptocurrecies, it is a good idea. Stake is one of them, you can deposit Doge and Shiba and take advantage of low fees of the Dogecoin blockchain, so there you have an option from an online casino which is quite popular around here.
Sure, Litecoin and Tron also offer very cheap deposits and fast transactions but since OP opened this topic to talk about memecoins I took the liberty to exclude Litecoin and Tron, since those are coins which are mostly taken seriously and are not memes.
On the other hand, Dogecoin community is very passionate and loyal, in my opinion. Even though, there are aware Dogecoin is a meme, they still want it to succeed and gain adoption within all kind of businesses, gambling included. I personally find amusing how serious businesses can accept Dogecoin. I am not against it, though.