I think it depends on each person's interests. I currently prefer slot gambling, where winning is purely based on luck, as there's no need for strategy or anything else that forces the brain to think. I just wait for a good spin and win.
It takes zero effort for the brain to process this and hence it is what the body likes to do which is why these games are so addictive. There are other games like dice which also follow the same procedure and hence always addictive if played for quite some time.
The games thag need some thinking like sports betting and poker they dont necessarily yield well to the ones with intelligence but specific skills related to that game. Of which I think sports does carry a lot of luck factor in it.