I feel like biggest advantages of using Bitcoin in online gambling platforms is to avoid some countries' regulations. It can be very hard to deposit local currency to bank account of gambling platforms. But its so much quicker and easier to do same with Bitcoin. Most countries don't follow Bitcoin transactions in such situations because its not exactly something illegal. Its legally grey area. It gives chance to many people around the world to gamble in 5 minutes.
Using bitcoins is an advantage for crypto gamblers as they do not need to transfer their bank accounts to online casinos and also it is safer from government tracking to banks. Apart from that, maybe it will also help reduce transaction costs that must be incurred by gamblers every time they deposit their money to play gambling. And even though bitcoin may not be illegal in that country, gamblers can still use it to play gambling because as long as the crypto casino doesn't prohibit users from that country from gambling in its casino, they can still gamble using bitcoin.
Having no geographic restrictions is definitely one of the best features of cryptocurrency casinos since almost anyone from any part of the world can utilize the platforms and gamble with ease since there are also no restrictions on cryptocurrency transactions. This has given a platform to everyone to be able to play games without any restrictions.
But I think there are still some casinos that don't allow some gamblers from some regions to play on their platform, this probably is because they require KYC for withdrawals and they are not able to verify some users based on their region.