Haha...I wouldn't single out any of them because the end of the day it is money we're talking about. And don't forget Cryptos can be bought to in s much as Fiat has a quality of being difficult to get. If it's your money then it's your money That's how i see it. Coz using $100 worth of BTC for betting wouldn't be any different from using same $100 in Fiat.
Whether fiat or cryptocurrency, both are money and none is bigger than the other when trying to earn it or get.
Moreover, you don't have to gamble with $100 before you gamble. One can gamble with as little as 10 dollars and still earn some money. It's all about the strategies you use.