My uncle gambled away a successful business, a beautiful house, his family, his friends. In my early memory he was a giant who carried me in the ocean, flying just above the breaking waves. Later on, when I was in elementary school, he lived with us for a bit. Some time later he lived in his Buick. He died alone and with nothing.
In my mind, we all should not allow a man to do that.
Banning addictive things isn't as straightforward as people love to believe. Even during the worst theocratic times, you could get alcohol in Saudi Arabia by asking the right people; and Saudi Arabia had way harsher means at its disposal than democratic countries do.
(For the complete picture, my grandpa drank himself to death at 57 and even though he used to have a good income, on the order of 3x as much as an average Czechoslovak worker of that time, he left almost nothing behind. All "liquefied". Other people were able to build family houses for their kids with less money.)
That might be the best solution to gambling. At least in Canada, casinos are very well advertised and glamorized. They're often run by the government, but they still market themselves to attract customers in a way you wouldn't expect of say, a safe opioid consumption site. Their slot machines are just as addictive. Sure, there's lip service paid to preventing gambling addiction, eg a piece of paper on the wall instructing patrons to play responsibly. But if we took the same attitude towards it as we do to tobacco, it might just fade away without all the downsides of prohibition.