My dad is addicted to a minecraft livestreamer, what do i do?

Tell him he should grow up and spend more time with his family or else you will all leave him for he is no man.

I know you already have a best answer for this, but I think you should tell him that it's okay to be interested in something, but he's going a little overboard with it and you as his son/daughter is feeling sad about it because you aren't getting the attention and affection you should be getting. Or you could even say you miss spending time with him. You could even add, "I want to spend time with you but I can't because you're always busy watching this live streamer and putting me as your second priority and that isn't fair." I hope this helps!

Nothing there's no problem