Betting in a casino is more risky, because in fact there is no strategy. In sports, you can win something, but if you carefully examine the players.
It is the advantage of betting with sports, you can do something just to win. You can do background checking for the teams involve and you can make your own choice on where you are comfortable to do so. In casino games, most of them are luck based except those card games that you can join, well there's a lot of choice of it, choose where you are good at.