Gambling addiction is different from drug addiction in terms of reasoning from someone who is into it. Addiction in gambling is because people are dissatisfied with what they already won in a gambling, and tend to lose it all even if they know they are not winning the game.
I think that gambling addiction is pretty similar to drug addiction, I mean it's the same chemicals that are released in the brain as when you do drugs.
What you're describing is a symptom of gambling addiction, not the root cause.
I'd say it's certainly possible that people turn to gambling and get addicted because they are dissatisfied with their life;
yes, gambling is more than just the game itself because of the addiction. I think most people start gambling initially for fun and sometimes they get carried away.