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.
This is where you make a mistake. When you place the bet in terms of fiat on sports betting and you've won it. Here you'll get the respective equivalent value. Same time if you've done the same in terms of bitcoin what you'll get is based on the market. Here it could go low as well as can increase. There is risk, but it is quite simple than betting on a gambling house that works with fiat.