I strongly believe that a lot of these new mobile games are heavily influencing kids to gamble. Their minds get very stimulated when they win virtual items like points, achievements, or gems. This isn't necessarily a bad thing though, as long we we teach them to gamble responsibly and treat it as a side hobby.
Besides that, I often heard from my friends who have kids, sometimes their kids buy something from the other kids to fill their bag with special character. I think this will make their kids spend more money than to enjoy the game. But I think it's okay because as long as they don't play gambling in the early ages

But I don't want to teach any kids to play gambling because once they enjoy with the game, then it will make them hard to stop them in the future.