Compared to the games of today available for kids, Candyland and its ilk sucked balls.
The problem is true interactivity and the influence of chance. Games children play today — especially electronic or video games — tend to reward decision-making and paying attention and decoding the environment of the game. Games like Candyland are 100% games of chance, with no hope of mastery and no reward for paying attention or experimenting.
Super Mario Brothers is a vastly more interesting task, cognitively speaking, than drawing cards and rolling dice.