I think that every person should make a living doing jobs like those of a streamer, but be honest and always put a warning, the game can make you addicted and you should avoid it, that is something that is very responsible, however telling lies like you say that there are people who say they always win or something to make advertising, that is very bad and unacceptable, in fact I am one of those who think that if you try to harm someone, that harm at some point in life is returned, and that is something that happens, so you have to know how to do advertising, know how to warn people and with that you can do a better job and you earn a very good reputation.
I totally agree with you. Those streamers think to be smart for deceiving their audience in exchange of easy and big money, but at some point they are going to face the consequences for their bad acts. It's an universal law which can't be avoided by anyone. There are actually honest and responsible ways to advertise gambling, so the issue here isn't gambling itself, but how it's being promoted on the internet and television. Most advertisements lack transparency nowadays, and that is what cause most criticizes against gambling.
At same time, I think it's good for people to stop idolizing celebrities, since these famous people just want to take advantage of them and grab their money. Society has an illusion that if someone is famous and appear on the television or at popular internet channels, they can be trusted. Unfortunatelly, it's still a strong common sense everywhere.