A caring father can hurt the child's development by making him feel too comfortable. You can show that you care by putting boundaries. I'm not sure the age matters here. You can cut down the internet, or make him pay rent. You can be hard, and at the same time give him options. Show him somehow that the reality could hit him in the face really hard, if he doesn't change.

There always could be depression behind things, so one has to be careful. Maybe arrange therapy, if necessary. For a young guy to be able to open up to his father could be really hard, especially if he's in a pinch, but acting as if you were a bystander isn't the solution.

(It seems the kid has autism according to the father, so it changes things quite a bit.)