I disagree that the parent has no role. If the child is blowing MY money on playing video games, I have a say in that. If it is his own money, well…he can be as stupid as he wants to be.
If the kid is staying up all night playing these stupid games, yes, it is time to tell him to knock it off or he is on his own, financially.
One of mine just left for campus and he left the video gaming systems at home, intentionally. His GPA is very high at the moment. He does have really good study habits though.