Some are unaware, but most probably just don't want to admit it
It's not without reason that addiction can be recognized from the start, but there are still many people with big egos who don't want to admit that they are addicted because they think that addiction is the worst condition and can be a disgrace for gamblers, so they don't want to admit it even though they are aware that they have been exposed to this.

It's possible that some people don't realize they've entered the stage of addiction, but on the other hand, when compared to those who have been aware from the start, I think we know that they know and are aware that their level of gambling is already very high. However, because of their big egos and unwillingness to admit that they are addicted, they prefer to let it go until it reaches a stage that is even worse.