A problem is infection. As Sports Betting is more legal and profitable, Fantasy Sports gain more Sports Bets and pseudoanonymity and lose some of their community spirit for "micro-transactions" and other "extreme gamification" and the line between each blurs. (Including to the point where groups looking for one might be easily confused into doing the other.)
I idly wonder if there is a way to shore up Fantasy Sports against the tide of Sports Betting profit.