I agree with your opinion, that a gambler will not become an addict if he is aware of all the risks when playing, if he plays too much, puts money in the hope of winning, of course that is impossible, on the contrary he will lose. all the money will be lost. And that will cause problems in his family and the problem in him is that he will regret having done that without thinking about other people.
In the case of gambling addicts they are harmful not only to the family but also to the society. At the beginning greed works in them to get more and when the rush reaches the point of desperation when everything is lost, taking a break from gambling will seem like the last thing you want, but it is necessary. Leaving gamblers after losing their large amount of money will give you the space and time to evaluate why it happened and how to prevent it from happening again. But a responsible gambler does not get greedy after earning a profit, they know the right rules of gambling so they are less likely to suffer.
Gambling addiction can really ruin a life and relationship. It can destroy you in every way possible and it can cause negative effect to the people close to you such as your family and to your friends. Addiction can bring trouble to you in terms of financial and even be a burden to your close ones because they might be the collateral damage for your irresponsibility. Greediness can bury you to pile of debts and loans. It will just bring you so much liabilities that might be too heavy to handle which could cost you a lot more later on. Self-reflection is much needed so that you won't be dependent to gambling.