Not really gambling specifically but I've seen tons of drug addicts recovering from their addiction. Recently saw one where the kid was forced to leave his dad (cause he was an addict) and a simple "I don't wanna" from the kid made the dad change. Find an anchor for those addicts, they help you recover.
One thing about some of these gambling stories and videos is that they are not shared by those affected for others to just hear their stories about how addicted they were, but they are shared to be used as educational materials for those who have lost their ways in gambling and believe they can't get out of it again. They are just showing that if they themselves can get out of it, then anyone can also do the same.
Some of the videos are also for the purpose of sharing information with those who are also entering gambling. If they aren't careful enough and don't follow the right steps, they might fall victim to gambling addiction and find it hard to get out of it. It all depends on how the viewers picture the story and what lesson they choose to learn from it.
Less of an educational thing but more of a push kind of idea. Most addicts just need that one push really, that push that's going to help them kickstart the process of recovery. Sadly said push can be hard to do and hard to find, even if you watch countless videos such as what OP posted. It all boils down to your capability of taking the first step. The rest? It just snowballs really. Each person has their own recovery method and process suitable for their current situation after all.