In YouTube and other social medias, the creator has an option to restrict minor to watch their videos, except the minor create a brand new account and fabricated their ages. If there's no warning message in their contents, it means the creator really don't care with the followers.
Well, there are only a few influencers who care and are concerned about their viewers, and I also understand why, because they only do it as work, as long as they make money, that's all that matters even though they know that the other promotions they do will cause harm to other viewers especially minors. What you mentioned is true because most of those who promote gambling use a set up accounts to make the promotion they share more believable, sometimes the other influencers don't really know anything about gambling, it seems like they just accepted the offer because it's giving them a huge compensation.
It's really easy to notice, when the streamers have no idea with something they promote, their eyes will look into other side (not the camera) because they need to deliver messages from the project.