He's completely cut himself off from certain genres of games because he personally doesn't want to play them. Even though he acknowledges that games like Divinity 2, League of Legends, Total War, Overwatch, Rainbow Six: Siege, Hearthstone, MTG: Arena, Rimworld, Space Engineers, etc, et-fucking-cetra are all incredibly popular. He has all of these games to choose from, yet he's willingly sticking to his corner of generic linear singleplayer shooters, ARPGs and platformers, because it's what's comfortable for him.
Why? He doesn't want to have his ego challenged by anything even remotely competitive or cerebral, because as I've said before, his ego is more important than money is to him. Money is the vehicle through which he either inflates his ego, or avoids the reality of his situation. He will consciously avoid or abandon anything that directly challenges his ego, even if it makes him a lot of money because the money is ultimately counterproductive if he's being made to look like an idiot every stream.