With Bitcoin, on the other hand, people may get aware about it only during their adulthood, so they will have more difficulties familiarizing with this.
Yeah, gambling is not that complicated like Bitcoin can be to everyone. As a kid everyone has experienced gambling in one way or the other. Bitcoin came into existence a decade back and most of the humanity still doesn't know that Bitcoin exist. Whereas if you ask about gambling to anyone on the street they would know about it. Although you wouldn't hear anything good about it. Comparing both doesn't make any sense for me. This is like comparing Bitcoin with gold wherein both are different entities.
As you said, gambling has been around for centuries, while Bitcoin is barely a decade and a half old, and gambling is an addictive activity that lures people in since it has the potential to provide significant profits while Bitcoin might be volatile but it doesn't guarantee very high returns on investments.