This is not a comparison as if they are the same. This is a comparison of experience on which oen gives more harm. So I do not think that we should raise an issue about this topic.
But I have entirely lost count of how many games and money which I have lost in gambling if I can recall correctly I can say I have lost more than I have ever won from gambling which has no means of coming back as they don’t create room for such.
Unless the person is impatience or has no knowledge of Bitcoin and has weak hands, he will never have any losses from Bitcoin because he will have the resistance to give in to FUD. So it is obvious that excessive gambling without any personal restraint can do more harm than trading Bitcoin.
On the other part, if a person does not know about bitcoin but still invest on it, and is shaken easily while he has more self-restraint in gambling andmoderate his gambling activity, the person could have more losses on Bitcoin trading.
So the answer is dependent on how a person deals with both entities.