Of course, bitcoin is what even made crypto casinos pop up from nowhere, because they saw the reason to set up online casinos that will accept bitcoin and most of them in the early days were NoKYC casino because that's what bitcoin represents (anonymous). Later, Ethereum came out and her children altcoins to give more options on coins to gamble with. Bitcoin really paved way for them just like it did for exchanges too.
It is simply mentioned that, it is possible to operate online crypto casinos without Bitcoin, but the acceptance of Bitcoin has made the casinos popular. Because nowadays the majority of people use Bitcoin. In those states where gambling is completely prohibited, those individuals can deposit funds into casinos without any complications. And they can bet without fear. However, for the convenience of gamblers, many casinos now also accept fiat currencies (only a few currencies).
I believe that, as technology advances, the use of Bitcoin will increase. For example: in all states, institutions, workplaces, and educational institutions. However, Bitcoin is not only convenient for casinos but also beneficial for gamblers.