Investing much time and money into gambling doesn't make us addicts. Successful gamblers have a life outside gambling; family, friend etc. They have fun times when they're not gambling. An addicted player, gives all to gambling and forfeits any other recreation that is not gambling. Their life revolves on gambling and they stake anything just to gamble. Such behaviour doesn't guarantee winning, a proof of success in gambling. If a person gives their all into gambling and doesn't win they're not successful, while being addicted to gamble. Hence if a person dedicates specific time on gambling and wins often, due to their extensive techniques of how gambing works. I'd add the person as a successful gambler. On the both sides, if a person is addicted and wins big too, they're successful gamblers. Because their addiction in gambling didn't end in playing games, but in devising methods that works for them. So, categorizing them, we can say that not all successful gamblers are addicts, same way not all addicts are successful gamblers. Even, a good percentage of successful gamblers play for fun.
If gamblers know that investing their time and money in gambling will not produce profits, they should look for other ways to make money and just need to take the time to find them. I agree that successful gamblers can use their time and money for other things outside of gambling to remain productive by looking for ways to make money other than gambling. They also won't experience addiction because they know how to use their time and money and can avoid or prevent gambling addiction. But gamblers who do not have self-control will be addicted to gambling without realizing it and will not do other things because, according to them, gambling is the most important thing.
Becoming a successful gambler requires many things that will be difficult to do and only those who have the ability can do it. But when they become successful gamblers, they can win compared to other gamblers and prevent many losses. They also have a balanced life between gambling and other things, so they don't experience gambling addiction.