Well, you are making sense but let me say that for an addiction to another thing to fuel addiction to gambling, I think it has alot to do with who the person is following, or keep as friends, and that or those friends have to be gamblers, this is the only way being addicted to alcohol (for example) can lead to being addicted to gambling as well because the friend you keep are likely also addicted to both.
Just like the saying that goes "show me your friends and I tell you who you are", some one who is addicted to alcohol may likely wake up one morning and decide to gamble, but trust, he wouldn't take gambling as serious as his alcohol, except there are alcoholic friends who are serious gamblers, this is where his addiction to gambling as well is going to come from.
While addicts often change company when they get rid of addiction, that addiction doesn't come from the friend circle. Addicts just choose addict friends because they are easier to get along with. They don't need to hide themselves from them. Addict friend circle also gives them patterns on their daily routines, and when someone gets something else to do they naturally distance themselves from the friendship as well.
Obviously some people, who blame others for their choices, blame the friend circle for that addiction. And they might even believe it because they aren't addicts when they aren't around them anymore. They could keep being addicts by themselves as well, and in many cases they will. It's just more fun to do with friends.
There are neurodivergent types, that copy their identities from other people, but even those don't copy the direct addiction. It's just a behavioral mirroring and in those cases company definitely defines what they do, but it's not as common, but i thought i should mention that there are exceptions where company defines how you behave.