It is said that people are slaves of habits side by side people can do anything they want. It is also not impossible in gambling. There can be no problem with controlled gambling. It also has no chance of becoming addictive. Nowadays gambling is also said to be a source of entertainment so enjoyment is not considered as addiction.
If they can do what they want then that is not a slavery but you are only a slave if you are being dictated by someone else (it can be another person or your own self/habit). Maybe some addicted people are now regretting and wanted to get out of their situation but they think it's hard and almost impossible because they are being dictated by their negative habits.
Concerned people can always help them anyway if they can't help their own selves. For those who have a control of themselves, they may have no problem for now but they shouldn't be overconfident and try to exceed within their limits as that is going to be the start for them to become addicted later on.