my brothers video game addiction is going to ruin his life

my brother is 18 has been gaming for maybe 5-6 years. he games ALL day everyday. i’m talking probably 10-12 hours every single day. he has a VERY addictive personality and has struggled with a binge eating disorder for as long as i can remember. he just recently got into smoking weed as well and instantly starting doing it all day every day. he’s been doing online school for the past 4 years and just recently graduated, and he has no ambition to do anything. he applied to a few jobs and didn’t hear anything back so he gave up. he had talked about starting classes at a community college, but every time i ask him about it he says he hasn’t even started to look into it. my parents have been enablers and have ignored this for years. im really really worried for him. he hardly goes out in public, doesnt have any relationships with people outside of my family in real life, and doesnt have any ambition to change this. i know this is an addiction and i want to handle it lightly, but i dont even know where to start.