This is just my own opinion but I suspect and by stats I’ve seen at some programs that offer such … that slots are most popular followed by video poker.
*for online gamblers. There’s no chance of counting cards at blackjack, and I suspect there are a lot of roulette players that don’t trust the virtual wheel like they do seeing the game in person at a real casino. Craps players are likely the same.
I imagine you lose a percentage of those players to distrust where as if you trust a slots or video poker game at a land-based casino …. you should have no trouble trusting the virtual sisters.
so then it comes down to the simple matter of whether the players trust to get paid …. not any doubts about the games.