Off course gambling is the worst addiction that you can have. Gambling in real world also is worst thing to follow. When you start with first round then you most probably loose the game and then afterwards you fight for your investment but meanwhile you start loosing your money and you don't even recognise that one. By the time you recognise you have lost then it is the time you find yourself addicted to the game and you start playing from the first round. You come online everyday and think that you will do best this time but the time never comes when you win. Lolz. Thats the funniest addiction you can have.
All the addictions do not bring something positive as they make the person depending on the object he is addicted to. I do not think that the crypto is the worst addiction, however.